Method and device for transmission/reception based on time unit group in wireless communication system

ABSTRACT

Disclosed are a method and a device for performing transmission/reception on the basis of a time unit group in a wireless communication system. According to one embodiment of the present disclosure, a method by which a terminal receives a downlink channel in a wireless communication system comprises the steps of: receiving configuration information about a slot group; monitoring a downlink control channel in one or more search space (SS) sets on the basis of the slot group; and receiving downlink control information (DCI) in the downlink control channel, wherein one or more from among the period, the offset and the duration of the SS sets can be set on the basis of granularity M (M is an integer greater than 1) of the slot group.

TECHNICAL FIELD

The present disclosure relates to a wireless communication system, andmore particularly, to a method and an apparatus for performingtransmission/reception based on a group of time units in a wirelesscommunication system.

BACKGROUND

A mobile communication system has been developed to provide a voiceservice while guaranteeing mobility of users. However, a mobilecommunication system has extended even to a data service as well as avoice service, and currently, an explosive traffic increase has causedshortage of resources and users have demanded a faster service, so amore advanced mobile communication system has been required.

The requirements of a next-generation mobile communication system atlarge should be able to support accommodation of explosive data traffic,a remarkable increase in a transmission rate per user, accommodation ofthe significantly increased number of connected devices, very lowEnd-to-End latency and high energy efficiency. To this end, a variety oftechnologies such as Dual Connectivity, Massive Multiple Input MultipleOutput (Massive MIMO), In-band Full Duplex, Non-Orthogonal MultipleAccess (NOMA), Super wideband Support, Device Networking, etc. have beenresearched.

SUMMARY

A technical object of the present disclosure is to provide a method andapparatus for transmitting/receiving based on a group of time units in awireless communication system.

An additional technical object of the present disclosure is to provide amethod and apparatus for transmitting a downlink control channel at atransmitting end and monitoring and receiving a downlink control channelat a receiving end based on a group of time units in a wirelesscommunication system.

An additional technical object of the present disclosure is to provide amethod and apparatus for transmitting/receiving a downlink controlchannel based on a search space set-related configuration based on agroup of time units in a wireless communication system.

An additional technical object of the present disclosure is to provide amethod and apparatus for performing uplink/downlinktransmission/reception based on timing related to a downlink controlchannel based on a group of time units in a wireless communicationsystem.

The technical objects to be achieved by the present disclosure are notlimited to the above-described technical objects, and other technicalobjects which are not described herein will be clearly understood bythose skilled in the pertinent art from the following description.

According to an aspect of the present disclosure, a method of receivinga downlink channel by terminal in a wireless communication system maycomprise: receiving configuration information for a slot group;monitoring a downlink control channel in at least one search space (SS)set, based on the slot group; and receiving downlink control information(DCI) in the downlink control channel, wherein at least one of a period,offset, or duration of the SS set is configured based on a granularity M(where M is an integer greater than 1) of the slot group.

According to another aspect of the present disclosure, a method oftransmitting a downlink channel by a base station in a wirelesscommunication system may comprise: transmitting to a terminalconfiguration information for a slot group; and transmitting a downlinkcontrol channel including downlink control information (DCI) in at leastone search space (SS) set, based on the slot group, wherein at least oneof a period, offset, or duration of the SS set is configured based on agranularity M (where M is an integer greater than 1) of the slot group.

According to an embodiment of the present disclosure, a method andapparatus for transmitting/receiving based on a group of time units in awireless communication system may be provided.

According to an embodiment of the present disclosure, a method andapparatus for transmitting a downlink control channel at a transmittingend and monitoring and receiving a downlink control channel at areceiving end based on a group of time units in a wireless communicationsystem may be provided.

According to an embodiment of the present disclosure, a method andapparatus for transmitting/receiving a downlink control channel based ona search space set-related configuration based on a group of time unitsin a wireless communication system may be provided.

According to an embodiment of the present disclosure, a method andapparatus for performing uplink/downlink transmission/reception based ontiming related to a downlink control channel based on a group of timeunits in a wireless communication system may be provided.

Effects achievable by the present disclosure are not limited to theabove-described effects, and other effects which are not describedherein may be clearly understood by those skilled in the pertinent artfrom the following description.

BRIEF DESCRIPTION OF DRAWINGS

Accompanying drawings included as part of detailed description forunderstanding the present disclosure provide embodiments of the presentdisclosure and describe technical features of the present disclosurewith detailed description.

FIG. 1 illustrates a structure of a wireless communication system towhich the present disclosure may be applied.

FIG. 2 illustrates a frame structure in a wireless communication systemto which the present disclosure may be applied.

FIG. 3 illustrates a resource grid in a wireless communication system towhich the present disclosure may be applied.

FIG. 4 illustrates a physical resource block in a wireless communicationsystem to which the present disclosure may be applied.

FIG. 5 illustrates a slot structure in a wireless communication systemto which the present disclosure may be applied.

FIG. 6 illustrates physical channels used in a wireless communicationsystem to which the present disclosure may be applied and a generalsignal transmission and reception method using them.

FIG. 7 is a diagram for explaining a method of transmitting or receivingby a terminal based on a group of time units according to an embodimentof the present disclosure.

FIG. 8 is a diagram for explaining a method of transmitting or receivingby a base station based on a group of time units according to anembodiment of the present disclosure.

FIG. 9 is a diagram illustrating a downlink control channel monitoringopportunity based on a group of time units according to an embodiment ofthe present disclosure.

FIG. 10 is a diagram for illustrating a signaling procedure of a basestation and a terminal according to an embodiment of the presentdisclosure.

FIG. 11 illustrates a block diagram of a wireless communication systemaccording to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, embodiments according to the present disclosure will bedescribed in detail by referring to accompanying drawings. Detaileddescription to be disclosed with accompanying drawings is to describeexemplary embodiments of the present disclosure and is not to representthe only embodiment that the present disclosure may be implemented. Thefollowing detailed description includes specific details to providecomplete understanding of the present disclosure. However, those skilledin the pertinent art knows that the present disclosure may beimplemented without such specific details.

In some cases, known structures and devices may be omitted or may beshown in a form of a block diagram based on a core function of eachstructure and device in order to prevent a concept of the presentdisclosure from being ambiguous.

In the present disclosure, when an element is referred to as being“connected”, “combined” or “linked” to another element, it may includean indirect connection relation that yet another element presentstherebetween as well as a direct connection relation. In addition, inthe present disclosure, a term, “include” or “have”, specifies thepresence of a mentioned feature, step, operation, component and/orelement, but it does not exclude the presence or addition of one or moreother features, stages, operations, components, elements and/or theirgroups.

In the present disclosure, a term such as “first”, “second”, etc. isused only to distinguish one element from other element and is not usedto limit elements, and unless otherwise specified, it does not limit anorder or importance, etc. between elements. Accordingly, within a scopeof the present disclosure, a first element in an embodiment may bereferred to as a second element in another embodiment and likewise, asecond element in an embodiment may be referred to as a first element inanother embodiment.

A term used in the present disclosure is to describe a specificembodiment, and is not to limit a claim. As used in a described andattached claim of an embodiment, a singular form is intended to includea plural form, unless the context clearly indicates otherwise. A termused in the present disclosure, “and/or”, may refer to one of relatedenumerated items or it means that it refers to and includes any and allpossible combinations of two or more of them. In addition, “/” betweenwords in the present disclosure has the same meaning as “and/or”, unlessotherwise described.

The present disclosure describes a wireless communication network or awireless communication system, and an operation performed in a wirelesscommunication network may be performed in a process in which a device(e.g., a base station) controlling a corresponding wirelesscommunication network controls a network and transmits or receives asignal, or may be performed in a process in which a terminal associatedto a corresponding wireless network transmits or receives a signal witha network or between terminals.

In the present disclosure, transmitting or receiving a channel includesa meaning of transmitting or receiving information or a signal through acorresponding channel. For example, transmitting a control channel meansthat control information or a control signal is transmitted through acontrol channel. Similarly, transmitting a data channel means that datainformation or a data signal is transmitted through a data channel.

Hereinafter, a downlink (DL) means a communication from a base stationto a terminal and an uplink (UL) means a communication from a terminalto a base station. In a downlink, a transmitter may be part of a basestation and a receiver may be part of a terminal. In an uplink, atransmitter may be part of a terminal and a receiver may be part of abase station. A base station may be expressed as a first communicationdevice and a terminal may be expressed as a second communication device.A base station (BS) may be substituted with a term such as a fixedstation, a Node B, an eNB (evolved-NodeB), a gNB (Next GenerationNodeB), a BTS (base transceiver system), an Access Point (AP), a Network(5G network), an AI (Artificial Intelligence) system/module, an RSU(road side unit), a robot, a drone (UAV: Unmanned Aerial Vehicle), an AR(Augmented Reality) device, a VR (Virtual Reality) device, etc. Inaddition, a terminal may be fixed or mobile, and may be substituted witha term such as a UE (User Equipment), an MS (Mobile Station), a UT (userterminal), an MSS (Mobile Subscriber Station), an SS(SubscriberStation), an AMS (Advanced Mobile Station), a WT (Wireless terminal), anMTC (Machine-Type Communication) device, an M2M (Machine-to-Machine)device, a D2D (Device-to-Device) device, a vehicle, an RSU (road sideunit), a robot, an AI (Artificial Intelligence) module, a drone (UAV:Unmanned Aerial Vehicle), an AR (Augmented Reality) device, a VR(Virtual Reality) device, etc.

The following description may be used for a variety of radio accesssystems such as CDMA, FDMA, TDMA, OFDMA, SC-FDMA, etc. CDMA may beimplemented by a wireless technology such as UTRA (Universal TerrestrialRadio Access) or CDMA2000. TDMA may be implemented by a radio technologysuch as GSM (Global System for Mobile communications)/GPRS (GeneralPacket Radio Service)/EDGE (Enhanced Data Rates for GSM Evolution).OFDMA may be implemented by a radio technology such as IEEE 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (Evolved UTRA), etc.UTRA is a part of a UMTS (Universal Mobile Telecommunications System).3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is apart of an E-UMTS (Evolved UMTS) using E-UTRA and LTE-A (Advanced)/LTE-Apro is an advanced version of 3GPP LTE. 3GPP NR(New Radio or New RadioAccess Technology) is an advanced version of 3GPP LTE/LTE-A/LTE-A pro.

To clarify description, it is described based on a 3GPP communicationsystem (e.g., LTE-A, NR), but a technical idea of the present disclosureis not limited thereto. LTE means a technology after 3GPP TS (TechnicalSpecification) 36.xxx Release 8. In detail, an LTE technology in orafter 3GPP TS 36.xxx Release 10 is referred to as LTE-A and an LTEtechnology in or after 3GPP TS 36.xxx Release 13 is referred to as LTE-Apro. 3GPP NR means a technology in or after TS 38.xxx Release 15. LTE/NRmay be referred to as a 3GPP system. “xxx” means a detailed number for astandard document. LTE/NR may be commonly referred to as a 3GPP system.For a background art, a term, an abbreviation, etc. used to describe thepresent disclosure, matters described in a standard document disclosedbefore the present disclosure may be referred to. For example, thefollowing document may be referred to.

For 3GPP LTE, TS 36.211 (physical channels and modulation), TS 36.212(multiplexing and channel coding), TS 36.213 (physical layerprocedures), TS 36.300 (overall description), TS 36.331 (radio resourcecontrol) may be referred to.

For 3GPP NR, TS 38.211 (physical channels and modulation), TS 38.212(multiplexing and channel coding), TS 38.213 (physical layer proceduresfor control), TS 38.214 (physical layer procedures for data), TS 38.300(NR and NG-RAN(New Generation-Radio Access Network) overalldescription), TS 38.331 (radio resource control protocol specification)may be referred to.

Abbreviations of terms which may be used in the present disclosure isdefined as follows.

-   -   BM: beam management    -   CQI Channel Quality Indicator    -   CRI channel state information—reference signal resource        indicator    -   CSI channel state information    -   CSI-IM channel state information—interference measurement    -   CSI-RS channel state information—reference signal    -   DMRS: demodulation reference signal    -   FDM: frequency division multiplexing    -   FFT: fast Fourier transform    -   IFDMA: interleaved frequency division multiple access    -   IFFT: inverse fast Fourier transform    -   L1-RSRP: Layer 1 reference signal received power    -   L1-RSRQ: Layer 1 reference signal received quality    -   MAC: medium access control    -   NZP: non-zero power    -   OFDM: orthogonal frequency division multiplexing    -   PDCCH: physical downlink control channel    -   PDSCH: physical downlink shared channel    -   PMI: precoding matrix indicator    -   RE: resource element    -   RI: Rank indicator    -   RRC: radio resource control    -   RSSI: received signal strength indicator    -   Rx: Reception    -   QCL: quasi co-location    -   SINR: signal to interference and noise ratio    -   SSB (or SS/PBCH block): Synchronization signal block (including        PSS (primary synchronization signal), SSS (secondary        synchronization signal) and PBCH (physical broadcast channel))    -   TDM: time division multiplexing    -   TRP: transmission and reception point    -   TRS: tracking reference signal    -   Tx: transmission    -   UE: user equipment    -   ZP: zero power

Overall System

As more communication devices have required a higher capacity, a needfor an improved mobile broadband communication compared to the existingradio access technology (RAT) has emerged. In addition, massive MTC(Machine Type Communications) providing a variety of services anytimeand anywhere by connecting a plurality of devices and things is also oneof main issues which will be considered in a next-generationcommunication. Furthermore, a communication system design considering aservice/a terminal sensitive to reliability and latency is alsodiscussed. As such, introduction of a next-generation RAT consideringeMBB (enhanced mobile broadband communication), mMTC (massive MTC),URLLC (Ultra-Reliable and Low Latency Communication), etc. is discussedand, for convenience, a corresponding technology is referred to as NR inthe present disclosure. NR is an expression which represents an exampleof a 5G RAT.

A new RAT system including NR uses an OFDM transmission method or atransmission method similar to it. A new RAT system may follow OFDMparameters different from OFDM parameters of LTE. Alternatively, a newRAT system follows a numerology of the existing LTE/LTE-A as it is, butmay support a wider system bandwidth (e.g., 100 MHz). Alternatively, onecell may support a plurality of numerologies. In other words, terminalswhich operate in accordance with different numerologies may coexist inone cell.

A numerology corresponds to one subcarrier spacing in a frequencydomain. As a reference subcarrier spacing is scaled by an integer N, adifferent numerology may be defined.

FIG. 1 illustrates a structure of a wireless communication system towhich the present disclosure may be applied.

In reference to FIG. 1 , NG-RAN is configured with gNBs which provide acontrol plane (RRC) protocol end for a NG-RA (NG-Radio Access) userplane (i.e., a new AS (access stratum) sublayer/PDCP (Packet DataConvergence Protocol)/RLC(Radio Link Control)/MAC/PHY) and UE. The gNBsare interconnected through a Xn interface. The gNB, in addition, isconnected to an NGC(New Generation Core) through an NG interface. Inmore detail, the gNB is connected to an AMF (Access and MobilityManagement Function) through an N2 interface, and is connected to a UPF(User Plane Function) through an N3 interface.

FIG. 2 illustrates a frame structure in a wireless communication systemto which the present disclosure may be applied.

A NR system may support a plurality of numerologies. Here, a numerologymay be defined by a subcarrier spacing and a cyclic prefix (CP)overhead. Here, a plurality of subcarrier spacings may be derived byscaling a basic (reference) subcarrier spacing by an integer N (or, μ).In addition, although it is assumed that a very low subcarrier spacingis not used in a very high carrier frequency, a used numerology may beselected independently from a frequency band. In addition, a variety offrame structures according to a plurality of numerologies may besupported in a NR system.

Hereinafter, an OFDM numerology and frame structure which may beconsidered in a NR system will be described. A plurality of OFDMnumerologies supported in a NR system may be defined as in the followingTable 1.

TABLE 1 μ Δf = 2^(μ) · 15 [kHz] CP 0 15 Normal 1 30 Normal 2 60 Normal,Extended 3 120 Normal 4 240 Normal

NR supports a plurality of numerologies (or subcarrier spacings (SCS))for supporting a variety of 5G services. For example, when a SCS is 15kHz, a wide area in traditional cellular bands is supported, and when aSCS is 30 kHz/60 kHz, dense-urban, lower latency and a wider carrierbandwidth are supported, and when a SCS is 60 kHz or higher, a bandwidthwider than 24.25 GHz is supported to overcome a phase noise.

An NR frequency band is defined as a frequency range in two types (FR1,FR2). FR1, FR2 may be configured as in the following Table 2. Inaddition, FR2 may mean a millimeter wave (mmW).

TABLE 2 Frequency Range Corresponding Subcarrier designation frequencyrange Spacing FR1  410 MHz-7125 MHz  15, 30, 60 kHz FR2 24250 MHz-52600MHz 60, 120, 240 kHz

Regarding a frame structure in an NR system, a size of a variety offields in a time domain is expresses as a multiple of a time unit ofT_(c)=1/(Δf_(max)·N_(f)). Here, Δf_(max) is 480·10³ Hz and N_(f) is4096. Downlink and uplink transmission is configured (organized) with aradio frame having a duration of T_(f)=1/(Δf_(max)N_(f)/100)·T_(c)=10ms. Here, a radio frame is configured with 10 subframes having aduration of T_(sf)=(Δf_(max)N_(f)/1000)·T_(c)=1 ms, respectively. Inthis case, there may be one set of frames for an uplink and one set offrames for a downlink. In addition, transmission in an uplink frame No.i from a terminal should start earlier byT_(TA)=(N_(TA)+N_(TA,offset))T_(c) than a corresponding downlink framein a corresponding terminal starts. For a subcarrier spacingconfiguration slots are numbered in an increasing order of n_(s)^(μ)∈{0, . . . , N_(slot) ^(subframe,μ)−1} in a subframe and arenumbered in an increasing order of n_(s,f) ^(μ)∈{0, . . . , N_(slot)^(frame,μ)−1} in a radio frame. One slot is configured with N_(symb)^(slot) consecutive OFDM symbols and N_(symb) ^(slot) is determinedaccording to CP. A start of a slot n_(s) ^(μ) in a subframe istemporally arranged with a start of an OFDM symbol n_(s) ^(μ)N_(symb)^(slot) in the same subframe. All terminals may not perform transmissionand reception at the same time, which means that all OFDM symbols of adownlink slot or an uplink slot may not be used.

Table 3 represents the number of OFDM symbols per slot (N_(symb)^(slot)) the number of slots per radio frame (N_(slot) ^(frame,μ)) andthe number of slots per subframe (N_(slot) ^(subframe,μ)) in a normal CPand Table 4 represents the number of OFDM symbols per slot, the numberof slots per radio frame and the number of slots per subframe in anextended CP.

TABLE 3 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16

TABLE 4 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)2 12 40 4

FIG. 2 is an example on μ=2 (SCS is 60 kHz), 1 subframe may include 4slots referring to Table 3. 1 subframe={1,2,4} slot shown in FIG. 2 isan example, the number of slots which may be included in 1 subframe isdefined as in Table 3 or Table 4. In addition, a mini-slot may include2, 4 or 7 symbols or more or less symbols.

Regarding a physical resource in a NR system, an antenna port, aresource grid, a resource element, a resource block, a carrier part,etc. may be considered. Hereinafter, the physical resources which may beconsidered in an NR system will be described in detail.

First, in relation to an antenna port, an antenna port is defined sothat a channel where a symbol in an antenna port is carried can beinferred from a channel where other symbol in the same antenna port iscarried. When a large-scale property of a channel where a symbol in oneantenna port is carried may be inferred from a channel where a symbol inother antenna port is carried, it may be said that 2 antenna ports arein a QC/QCL (quasi co-located or quasi co-location) relationship. Inthis case, the large-scale property includes at least one of delayspread, doppler spread, frequency shift, average received power,received timing.

FIG. 3 illustrates a resource grid in a wireless communication system towhich the present disclosure may be applied.

In reference to FIG. 3 , it is illustratively described that a resourcegrid is configured with N_(RB) ^(μ)N_(sc) ^(RB) subcarriers in afrequency domain and one subframe is configured with 14·2^(μ) OFDMsymbols, but it is not limited thereto. In an NR system, a transmittedsignal is described by OFDM symbols of 2^(μ)N_(symb) ^((μ)) and one ormore resource grids configured with N_(RB) ^(μ)N_(sc) ^(RB) subcarriers.Here, N_(RB) ^(μ)≤N_(RB) ^(max,μ). The N_(RB) ^(max,μ) represents amaximum transmission bandwidth, which may be different between an uplinkand a downlink as well as between numerologies. In this case, oneresource grid may be configured per μ and antenna port p. Each elementof a resource grid for μ and an antenna port p is referred to as aresource element and is uniquely identified by an index pair (k,l′).Here, k=0, . . . , N_(RB) ^(μ)N_(sc) ^(RB)−1 is an index in a frequencydomain and l′=0, . . . , 2^(μ)N_(symb) ^((μ))−1 refers to a position ofa symbol in a subframe. When referring to a resource element in a slot,an index pair (k,l) is used. Here, l=0, . . . , N_(symb) ^(μ)−1. Aresource element (k,l′) for μ and an antenna port p corresponds to acomplex value, a_(k,l′) ^((p,μ)). When there is no risk of confusion orwhen a specific antenna port or numerology is not specified, indexes pand μ may be dropped, whereupon a complex value may be a_(k,l′) ^((p))or a_(k,l′). In addition, a resource block (RB) is defined as N_(sc)^(RB)=12 consecutive subcarriers in a frequency domain.

Point A plays a role as a common reference point of a resource blockgrid and is obtained as follows.

-   -   offsetToPointA for a primary cell (PCell) downlink represents a        frequency offset between point A and the lowest subcarrier of        the lowest resource block overlapped with a SS/PBCH block which        is used by a terminal for an initial cell selection. It is        expressed in resource block units assuming a 15 kHz subcarrier        spacing for FR1 and a 60 kHz subcarrier spacing for FR2.    -   absoluteFrequencyPointA represents a frequency-position of point        A expressed as in ARFCN (absolute radio-frequency channel        number).

Common resource blocks are numbered from 0 to the top in a frequencydomain for a subcarrier spacing configuration μ. The center ofsubcarrier 0 of common resource block 0 for a subcarrier spacingconfiguration μ is identical to ‘point A’. A relationship between acommon resource block number n_(CRB) ^(μ) and a resource element (k,l)for a subcarrier spacing configuration μ in a frequency domain is givenas in the following Equation 1.

$\begin{matrix}{n_{CRB}^{\mu} = \left\lfloor \frac{k}{N_{sc}^{RB}} \right\rfloor} & \left\lbrack {{Equation}1} \right\rbrack\end{matrix}$

In Equation 1, k is defined relatively to point A so that k=0corresponds to a subcarrier centering in point A. Physical resourceblocks are numbered from 0 to N_(BWP,i) ^(size,μ)−1 in a bandwidth part(BWP) and i is a number of a BWP. A relationship between a physicalresource block n_(PRB) and a common resource block n_(CRB) in BWP i isgiven by the following Equation 2.

n _(CRB) ^(μ) =n _(PRB) ^(μ) +N _(BWP,i) ^(start,μ)  [Equation 2]

N_(BWP,i) ^(start,μ) is a common resource block that a BWP startsrelatively to common resource block 0.

FIG. 4 illustrates a physical resource block in a wireless communicationsystem to which the present disclosure may be applied. And, FIG. 5illustrates a slot structure in a wireless communication system to whichthe present disclosure may be applied.

In reference to FIG. 4 and FIG. 5 , a slot includes a plurality ofsymbols in a time domain. For example, for a normal CP, one slotincludes 7 symbols, but for an extended CP, one slot includes 6 symbols.

A carrier includes a plurality of subcarriers in a frequency domain. AnRB (Resource Block) is defined as a plurality of (e.g., 12) consecutivesubcarriers in a frequency domain. A BWP (Bandwidth Part) is defined asa plurality of consecutive (physical) resource blocks in a frequencydomain and may correspond to one numerology (e.g., an SCS, a CP length,etc.). A carrier may include a maximum N (e.g., 5) BWPs. A datacommunication may be performed through an activated BWP and only one BWPmay be activated for one terminal. In a resource grid, each element isreferred to as a resource element (RE) and one complex symbol may bemapped.

In an NR system, up to 400 MHz may be supported per component carrier(CC). If a terminal operating in such a wideband CC always operatesturning on a radio frequency (FR) chip for the whole CC, terminalbattery consumption may increase. Alternatively, when severalapplication cases operating in one wideband CC (e.g., eMBB, URLLC, Mmtc,V2X, etc.) are considered, a different numerology (e.g., a subcarrierspacing, etc.) may be supported per frequency band in a correspondingCC. Alternatively, each terminal may have a different capability for themaximum bandwidth. By considering it, a base station may indicate aterminal to operate only in a partial bandwidth, not in a full bandwidthof a wideband CC, and a corresponding partial bandwidth is defined as abandwidth part (BWP) for convenience. A BWP may be configured withconsecutive RBs on a frequency axis and may correspond to one numerology(e.g., a subcarrier spacing, a CP length, a slot/a mini-slot duration).

Meanwhile, a base station may configure a plurality of BWPs even in oneCC configured to a terminal. For example, a BWP occupying a relativelysmall frequency domain may be configured in a PDCCH monitoring slot, anda PDSCH indicated by a PDCCH may be scheduled in a greater BWP.Alternatively, when UEs are congested in a specific BWP, some terminalsmay be configured with other BWP for load balancing. Alternatively,considering frequency domain inter-cell interference cancellationbetween neighboring cells, etc., some middle spectrums of a fullbandwidth may be excluded and BWPs on both edges may be configured inthe same slot. In other words, a base station may configure at least oneDL/UL BWP to a terminal associated with a wideband CC. A base stationmay activate at least one DL/UL BWP of configured DL/UL BWP(s) at aspecific time (by L1 signaling or MAC CE (Control Element) or RRCsignaling, etc.). In addition, a base station may indicate switching toother configured DL/UL BWP (by L1 signaling or MAC CE or RRC signaling,etc.). Alternatively, based on a timer, when a timer value is expired,it may be switched to a determined DL/UL BWP. Here, an activated DL/ULBWP is defined as an active DL/UL BWP. But, a configuration on a DL/ULBWP may not be received when a terminal performs an initial accessprocedure or before a RRC connection is set up, so a DL/UL BWP which isassumed by a terminal under these situations is defined as an initialactive DL/UL BWP.

FIG. 6 illustrates physical channels used in a wireless communicationsystem to which the present disclosure may be applied and a generalsignal transmission and reception method using them.

In a wireless communication system, a terminal receives informationthrough a downlink from a base station and transmits information throughan uplink to a base station. Information transmitted and received by abase station and a terminal includes data and a variety of controlinformation and a variety of physical channels exist according to atype/a usage of information transmitted and received by them.

When a terminal is turned on or newly enters a cell, it performs aninitial cell search including synchronization with a base station or thelike (S601). For the initial cell search, a terminal may synchronizewith a base station by receiving a primary synchronization signal (PSS)and a secondary synchronization signal (SSS) from a base station andobtain information such as a cell identifier (ID), etc. After that, aterminal may obtain broadcasting information in a cell by receiving aphysical broadcast channel (PBCH) from a base station. Meanwhile, aterminal may check out a downlink channel state by receiving a downlinkreference signal (DL RS) at an initial cell search stage.

A terminal which completed an initial cell search may obtain moredetailed system information by receiving a physical downlink controlchannel (PDCCH) and a physical downlink shared channel (PDSCH) accordingto information carried in the PDCCH (S602).

Meanwhile, when a terminal accesses to a base station for the first timeor does not have a radio resource for signal transmission, it mayperform a random access (RACH) procedure to a base station (S603 toS606). For the random access procedure, a terminal may transmit aspecific sequence as a preamble through a physical random access channel(PRACH) (S603 and S605) and may receive a response message for apreamble through a PDCCH and a corresponding PDSCH (S604 and S606). Acontention based RACH may additionally perform a contention resolutionprocedure.

A terminal which performed the above-described procedure subsequentlymay perform PDCCH/PDSCH reception (S607) and PUSCH (Physical UplinkShared Channel)/PUCCH (physical uplink control channel) transmission(S608) as a general uplink/downlink signal transmission procedure. Inparticular, a terminal receives downlink control information (DCI)through a PDCCH. Here, DCI includes control information such as resourceallocation information for a terminal and a format varies depending onits purpose of use.

Meanwhile, control information which is transmitted by a terminal to abase station through an uplink or is received by a terminal from a basestation includes a downlink/uplink ACK/NACK(Acknowledgement/Non-Acknowledgement) signal, a CQI (Channel QualityIndicator), a PMI (Precoding Matrix Indicator), a RI (Rank Indicator),etc. For a 3GPP LTE system, a terminal may transmit control informationof the above-described CQI/PMI/RI, etc. through a PUSCH and/or a PUCCH.

Table 5 represents an example of a DCI format in an NR system.

TABLE 5 DCI Format Use 0_0 Scheduling of a PUSCH in one cell 0_1Scheduling of one or multiple PUSCHs in one cell, or indication of cellgroup downlink feedback information to a UE 0_2 Scheduling of a PUSCH inone cell 1_0 Scheduling of a PDSCH in one DL cell 1_1 Scheduling of aPDSCH in one cell 1_2 Scheduling of a PDSCH in one cell

In reference to Table 5, DCI formats 0_0, 0_1 and 0_2 may includeresource information (e.g., UL/SUL (Supplementary UL), frequencyresource allocation, time resource allocation, frequency hopping, etc.),information related to a transport block (TB) (e.g., MCS (ModulationCoding and Scheme), a NDI (New Data Indicator), a RV (RedundancyVersion), etc.), information related to a HARQ (Hybrid—Automatic Repeatand request) (e.g., a process number, a DAI (Downlink Assignment Index),PDSCH-HARQ feedback timing, etc.), information related to multipleantennas (e.g., DMRS sequence initialization information, an antennaport, a CSI request, etc.), power control information (e.g., PUSCH powercontrol, etc.) related to scheduling of a PUSCH and control informationincluded in each DCI format may be pre-defined.

DCI format 0_0 is used for scheduling of a PUSCH in one cell.Information included in DCI format 0_0 is CRC (cyclic redundancy check)scrambled by a C-RNTI (Cell Radio Network Temporary Identifier) or aCS-RNTI (Configured Scheduling RNTI) or a MCS-C-RNTI (Modulation CodingScheme Cell RNTI) and transmitted.

DCI format 0_1 is used to indicate scheduling of one or more PUSCHs orconfigure grant (CG) downlink feedback information to a terminal in onecell. Information included in DCI format 0_1 is CRC scrambled by aC-RNTI or a CS-RNTI or a SP-CSI-RNTI (Semi-Persistent CSI RNTI) or aMCS-C-RNTI and transmitted.

DCI format 0_2 is used for scheduling of a PUSCH in one cell.Information included in DCI format 0_2 is CRC scrambled by a C-RNTI or aCS-RNTI or a SP-CSI-RNTI or a MCS-C-RNTI and transmitted.

Next, DCI formats 1_0, 1_1 and 1_2 may include resource information(e.g., frequency resource allocation, time resource allocation, VRB(virtual resource block)-PRB (physical resource block) mapping, etc.),information related to a transport block (TB)(e.g., MCS, NDI, RV, etc.),information related to a HARQ (e.g., a process number, DAI, PDSCH-HARQfeedback timing, etc.), information related to multiple antennas (e.g.,an antenna port, a TCI (transmission configuration indicator), a SRS(sounding reference signal) request, etc.), information related to aPUCCH (e.g., PUCCH power control, a PUCCH resource indicator, etc.)related to scheduling of a PDSCH and control information included ineach DCI format may be pre-defined.

DCI format 1_0 is used for scheduling of a PDSCH in one DL cell.Information included in DCI format 1_0 is CRC scrambled by a C-RNTI or aCS-RNTI or a MCS-C-RNTI and transmitted.

DCI format 1_1 is used for scheduling of a PDSCH in one cell.Information included in DCI format 1_1 is CRC scrambled by a C-RNTI or aCS-RNTI or a MCS-C-RNTI and transmitted.

DCI format 1_2 is used for scheduling of a PDSCH in one cell.Information included in DCI format 1_2 is CRC scrambled by a C-RNTI or aCS-RNTI or a MCS-C-RNTI and transmitted.

Operation Related to Multi-TRPs

A coordinated multi point (CoMP) scheme refers to a scheme in which aplurality of base stations effectively control interference byexchanging (e.g., using an X2 interface) or utilizing channelinformation (e.g., RI/CQI/PMI/LI (layer indicator), etc.) fed back by aterminal and cooperatively transmitting to a terminal. According to ascheme used, a CoMP may be classified into joint transmission (JT),coordinated Scheduling (CS), coordinated Beamforming (CB), dynamic PointSelection (DPS), dynamic Point Blocking (DPB), etc.

M-TRP transmission schemes that M TRPs transmit data to one terminal maybe largely classified into i) eMBB M-TRP transmission, a scheme forimproving a transfer rate, and ii) URLLC M-TRP transmission, a schemefor increasing a reception success rate and reducing latency.

In addition, with regard to DCI transmission, M-TRP transmission schemesmay be classified into i) M-TRP transmission based on M-DCI (multipleDCI) that each TRP transmits different DCIs and ii) M-TRP transmissionbased on S-DCI (single DCI) that one TRP transmits DCI. For example, forS-DCI based M-TRP transmission, all scheduling information on datatransmitted by M TRPs should be delivered to a terminal through one DCI,it may be used in an environment of an ideal BackHaul (ideal BH) wheredynamic cooperation between two TRPs is possible.

For TDM based URLLC M-TRP transmission, scheme 3/4 is under discussionfor standardization. Specifically, scheme 4 means a scheme in which oneTRP transmits a transport block (TB) in one slot and it has an effect toimprove a probability of data reception through the same TB receivedfrom multiple TRPs in multiple slots. Meanwhile, scheme 3 means a schemein which one TRP transmits a TB through consecutive number of OFDMsymbols (i.e., a symbol group) and TRPs may be configured to transmitthe same TB through a different symbol group in one slot.

In addition, UE may recognize PUSCH (or PUCCH) scheduled by DCI receivedin different control resource sets (CORESETs)(or CORESETs belonging todifferent CORESET groups) as PUSCH (or PUCCH) transmitted to differentTRPs or may recognize PDSCH (or PDCCH) from different TRPs. In addition,the below-described method for UL transmission (e.g., PUSCH/PUCCH)transmitted to different TRPs may be applied equivalently to ULtransmission (e.g., PUSCH/PUCCH)transmitted to different panelsbelonging to the same TRP.

Hereinafter, multiple DCI based non-coherent joint transmission(NCJT)/single DCI based NCJT will be described.

NCJT (Non-coherent joint transmission) is a scheme in which a pluralityof transmission points (TP) transmit data to one terminal by using thesame time frequency resource, TPs transmit data by using a differentDMRS (Demodulation Multiplexing Reference Signal) between TPs through adifferent layer (i.e., through a different DMRS port).

A TP delivers data scheduling information through DCI to a terminalreceiving NCJT. Here, a scheme in which each TP participating in NCJTdelivers scheduling information on data transmitted by itself throughDCI is referred to as ‘multi DCI based NCJT’. As each of N TPsparticipating in NCJT transmission transmits DL grant DCI and a PDSCH toUE, UE receives N DCI and N PDSCHs from N TPs. Meanwhile, a scheme inwhich one representative TP delivers scheduling information on datatransmitted by itself and data transmitted by a different TP (i.e., a TPparticipating in NCJT) through one DCI is referred to as ‘single DCIbased NCJT’. Here, N TPs transmit one PDSCH, but each TP transmits onlysome layers of multiple layers included in one PDSCH. For example, when4-layer data is transmitted, TP 1 may transmit 2 layers and TP 2 maytransmit 2 remaining layers to UE.

Multiple TRPs (MTRPs) performing NCJT transmission may transmit DL datato a terminal by using any one scheme of the following two schemes.

First, ‘a single DCI based MTRP scheme’ is described. MTRPscooperatively transmit one common PDSCH and each TRP participating incooperative transmission spatially partitions and transmits acorresponding PDSCH into different layers (i.e., different DMRS ports)by using the same time frequency resource. Here, scheduling informationon the PDSCH is indicated to UE through one DCI and which DMRS (group)port uses which QCL RS and QCL type information is indicated by thecorresponding DCI (which is different from DCI indicating a QCL RS and atype which will be commonly applied to all DMRS ports indicated as inthe existing scheme). In other words, M TCI states may be indicatedthrough a TCI (Transmission Configuration Indicator) field in DCI (e.g.,for 2 TRP cooperative transmission, M=2) and a QCL RS and a type may beindicated by using M different TCI states for M DMRS port group. Inaddition, DMRS port information may be indicated by using a new DMRStable.

Next, ‘a multiple DCI based MTRP scheme’ is described. Each of MTRPstransmits different DCI and PDSCH and (part or all of) the correspondingPDSCHs are overlapped each other and transmitted in a frequency timeresource. Corresponding PDSCHs may be scrambled through a differentscrambling ID (identifier) and the DCI may be transmitted through aCORESET belonging to a different CORESET group. (Here, a CORESET groupmay be identified by an index defined in a CORESET configuration of eachCORESET. For example, when index=0 is configured for CORESETs 1 and 2and index=1 is configured for CORESETs 3 and 4, CORESETs 1 and 2 areCORESET group 0 and CORESET 3 and 4 belong to a CORESET group 1. Inaddition, when an index is not defined in a CORESET, it may be construedas index=0) When a plurality of scrambling IDs are configured or two ormore CORESET groups are configured in one serving cell, a UE may noticethat it receives data according to a multiple DCI based MTRP operation.

Alternatively, whether of a single DCI based MTRP scheme or a multipleDCI based MTRP scheme may be indicated to UE through separate signaling.In an example, for one serving cell, a plurality of CRS (cell referencesignal) patterns may be indicated to UE for a MTRP operation. In thiscase, PDSCH rate matching for a CRS may be different depending on asingle DCI based MTRP scheme or a multiple DCI based MTRP scheme(because a CRS pattern is different).

Hereinafter, a CORESET group ID described/mentioned in the presentdisclosure may mean an index/identification information (e.g., an ID,etc.) for distinguishing a CORESET for each TRP/panel. In addition, aCORESET group may be a group/union of CORESET distinguished by anindex/identification information (e.g., an ID)/the CORESET group ID,etc. for distinguishing a CORESET for each TRP/panel. In an example, aCORESET group ID may be specific index information defined in a CORESETconfiguration. In this case, a CORESET group may beconfigured/indicated/defined by an index defined in a CORESETconfiguration for each CORESET. Additionally/alternatively, a CORESETgroup ID may mean an index/identification information/an indicator, etc.for distinguishment/identification between CORESETsconfigured/associated with each TRP/panel. Hereinafter, a CORESET groupID described/mentioned in the present disclosure may be expressed bybeing substituted with a specific index/specific identificationinformation/a specific indicator for distinguishment/identificationbetween CORESETs configured/associated with each TRP/panel. The CORESETgroup ID, i.e., a specific index/specific identification information/aspecific indicator for distinguishment/identification between CORESETsconfigured/associated with each TRP/panel may be configured/indicated toa terminal through higher layer signaling (e.g., RRC signaling)/L2signaling (e.g., MAC-CE)/L1 signaling (e.g., DCI), etc. In an example,it may be configured/indicated so that PDCCH detection will be performedper each TRP/panel in a unit of a corresponding CORESET group (i.e., perTRP/panel belonging to the same CORESET group).Additionally/alternatively, it may be configured/indicated so thatuplink control information (e.g., CSI, HARQ-A/N (ACK/NACK), SR(scheduling request)) and/or uplink physical channel resources (e.g.,PUCCH/PRACH/SRS resources) are separated and managed/controlled per eachTRP/panel in a unit of a corresponding CORESET group (i.e., perTRP/panel belonging to the same CORESET group).Additionally/alternatively, HARQ A/N (process/retransmission) forPDSCH/PUSCH, etc. scheduled per each TRP/panel may be managed percorresponding CORESET group (i.e., per TRP/panel belonging to the sameCORESET group).

Hereinafter, partially overlapped NCJT will be described.

In addition, NCJT may be classified into fully overlapped NCJT that timefrequency resources transmitted by each TP are fully overlapped andpartially overlapped NCJT that only some time frequency resources areoverlapped. In other words, for partially overlapped NCJT, data of bothof TP 1 and TP 2 are transmitted in some time frequency resources anddata of only one TP of TP 1 or TP 2 is transmitted in remaining timefrequency resources.

Hereinafter, a method for improving reliability in Multi-TRP will bedescribed.

As a transmission and reception method for improving reliability usingtransmission in a plurality of TRPs, the following two methods may beconsidered.

FIG. 7 illustrates a method of multiple TRPs transmission in a wirelesscommunication system to which the present disclosure may be applied.

In reference to FIG. 7(a), it is shown a case in which layer groupstransmitting the same codeword (CW)/transport block (TB) correspond todifferent TRPs. Here, a layer group may mean a predetermined layer setincluding one or more layers. In this case, there is an advantage thatthe amount of transmitted resources increases due to the number of aplurality of layers and thereby a robust channel coding with a lowcoding rate may be used for a TB, and additionally, because a pluralityof TRPs have different channels, it may be expected to improvereliability of a received signal based on a diversity gain.

In reference to FIG. 7(b), an example that different CWs are transmittedthrough layer groups corresponding to different TRPs is shown. Here, itmay be assumed that a TB corresponding to CW #1 and CW #2 in the drawingis identical to each other. In other words, CW #1 and CW #2 mean thatthe same TB is respectively transformed through channel coding, etc.into different CWs by different TRPs. Accordingly, it may be consideredas an example that the same TB is repetitively transmitted. In case ofFIG. 7(b), it may have a disadvantage that a code rate corresponding toa TB is higher compared to FIG. 7(a). However, it has an advantage thatit may adjust a code rate by indicating a different RV (redundancyversion) value or may adjust a modulation order of each CW for encodedbits generated from the same TB according to a channel environment.

According to methods illustrated in FIG. 7(a) and FIG. 7(b) above,probability of data reception of a terminal may be improved as the sameTB is repetitively transmitted through a different layer group and eachlayer group is transmitted by a different TRP/panel. It is referred toas a SDM (Spatial Division Multiplexing) based M-TRP URLLC transmissionmethod. Layers belonging to different layer groups are respectivelytransmitted through DMRS ports belonging to different DMRS CDM groups.

In addition, the above-described contents related to multiple TRPs aredescribed based on an SDM (spatial division multiplexing) method usingdifferent layers, but it may be naturally extended and applied to a FDM(frequency division multiplexing) method based on a different frequencydomain resource (e.g., RB/PRB (set), etc.) and/or a TDM (time divisionmultiplexing) method based on a different time domain resource (e.g., aslot, a symbol, a sub-symbol, etc.).

Regarding a method for multiple TRPs based URLLC scheduled by singleDCI, the following method is discussed.

1) Method 1 (SDM): Time and Frequency Resource Allocation is Overlappedand n (n<=Ns) TCI States in a Single Slot

1-a) Method 1a

-   -   The same TB is transmitted in one layer or layer set at each        transmission time (occasion) and each layer or each layer set is        associated with one TCI and one set of DMRS port(s).    -   A single codeword having one RV is used in all spatial layers or        all layer sets. With regard to UE, different coded bits are        mapped to a different layer or layer set by using the same        mapping rule.

1-b) Method 1b

-   -   The same TB is transmitted in one layer or layer set at each        transmission time (occasion) and each layer or each layer set is        associated with one TCI and one set of DMRS port(s).    -   A single codeword having one RV is used in each spatial layer or        each layer set. RV(s) corresponding to each spatial layer or        each layer set may be the same or different.

1-c) Method 1c

-   -   At one transmission time (occasion), the same TB having one DMRS        port associated with multiple TCI state indexes is transmitted        in one layer or the same TB having multiple DMRS ports        one-to-one associated with multiple TCI state indexes is        transmitted in one layer.

In case of the method 1a and 1c, the same MCS is applied to all layersor all layer sets.

2) Method 2 (FDM): Frequency Resource Allocation is not Overlapped and n(n<=ND TCI States in a Single Slot

-   -   Each non-overlapping frequency resource allocation is associated        with one TCI state.    -   The same single/multiple DMRS port(s) are associated with all        non-overlapping frequency resource allocation.

2-a) Method 2a

-   -   A single codeword having one RV is used for all resource        allocation. With regard to UE, common RB matching (mapping of a        codeword to a layer) is applied to all resource allocation.

2-b) Method 2b

-   -   A single codeword having one RV is used for each non-overlapping        frequency resource allocation. A RV corresponding to each        non-overlapping frequency resource allocation may be the same or        different.

For the method 2a, the same MCS is applied to all non-overlappingfrequency resource allocation.

3) Method 3 (TDM): Time Resource Allocation is not Overlapped and n(n<=Nt1) TCI States in a Single Slot

-   -   Each transmission time (occasion) of a TB has time granularity        of a mini-slot and has one TCI and one RV.    -   A common MCS is used with a single or multiple DMRS port(s) at        every transmission time (occasion) in a slot.    -   A RV/TCI may be the same or different at a different        transmission time (occasion).

4) Method 4 (TDM): n (n<=Nt2) TCI States in K (n<=K) Different Slots

-   -   Each transmission time (occasion) of a TB has one TCI and one        RV.    -   Every transmission time (occasion) across K slots uses a common        MCS with a single or multiple DMRS port(s).    -   A RV/TCI may be the same or different at a different        transmission time (occasion).

Hereinafter, MTRP URLLC is described.

In the present disclosure, DL MTRP URLLC means that multiple TRPstransmit the same data (e.g., the same TB)/DCI by using a differentlayer/time/frequency resource. For example, TRP 1 transmits the samedata/DCI in resource 1 and TRP 2 transmits the same data/DCI in resource2. UE configured with a DL MTRP-URLLC transmission method receives thesame data/DCI by using a different layer/time/frequency resource. Here,UE is configured from a base station for which QCL RS/type (i.e., a DLTCI state) should be used in a layer/time/frequency resource receivingthe same data/DCI. For example, when the same data/DCI is received inresource 1 and resource 2, a DL TCI state used in resource 1 and a DLTCI state used in resource 2 may be configured. UE may achieve highreliability because it receives the same data/DCI through resource 1 andresource 2. Such DL MTRP URLLC may be applied to a PDSCH/a PDCCH.

And, in the present disclosure, UL MTRP-URLLC means that multiple TRPsreceive the same data/UCI (uplink control information) from any UE byusing a different layer/time/frequency resource. For example, TRP 1receives the same data/DCI from UE in resource 1 and TRP 2 receives thesame data/DCI from UE in resource 2 to share received data/DCI through abackhaul link connected between TRPs. UE configured with a UL MTRP-URLLCtransmission method transmits the same data/UCI by using a differentlayer/time/frequency resource. In this case, UE is configured from abase station for which Tx beam and which Tx power (i.e., a UL TCI state)should be used in a layer/time/frequency resource transmitting the samedata/DCI. For example, when the same data/UCI is transmitted in resource1 and resource 2, a UL TCI state used in resource 1 and a UL TCI stateused in resource 2 may be configured. Such UL MTRP URLLC may be appliedto a PUSCH/a PUCCH.

In addition, in the present disclosure, when a specific TCI state (orTCI) is used (or mapped) in receiving data/DCI/UCI for anyfrequency/time/space resource (layer), it means as follows. For a DL, itmay mean that a channel is estimated from a DMRS by using a QCL type anda QCL RS indicated by a corresponding TCI state in thatfrequency/time/space resource (layer) and data/DCI isreceived/demodulated based on an estimated channel. In addition, for aUL, it may mean that a DMRS and data/UCI are transmitted/modulated byusing a Tx beam and power indicated by a corresponding TCI state in thatfrequency/time/space resource.

Here, an UL TCI state has Tx beam and/or Tx power information of UE andmay configure spatial relation information, etc. to UE through otherparameter, instead of a TCI state. An UL TCI state may be directlyindicated by UL grant DCI or may mean spatial relation information of aSRS resource indicated by a SRI (sounding resource indicator) field ofUL grant DCI. Alternatively, it may mean an open loop (OL) Tx powercontrol parameter connected to a value indicated by a SRI field of ULgrant DCI (e.g., j: an index for open loop parameter Po and alpha (up to32 parameter value sets per cell), q_d: an index of a DL RS resource forPL (pathloss) measurement (up to 4 measurements per cell), l: a closedloop power control process index (up to 2 processes per cell)).

Hereinafter, MTRP eMBB is described.

In the present disclosure, MTRP-eMBB means that multiple TRPs transmitdifferent data (e.g., a different TB) by using a differentlayer/time/frequency. UE configured with a MTRP-eMBB transmission methodreceives an indication on multiple TCI states through DCI and assumesthat data received by using a QCL RS of each TCI state is differentdata.

On the other hand, UE may figure out whether of MTRP URLLCtransmission/reception or MTRP eMBB transmission/reception by separatelydividing a RNTI for MTRP-URLLC and a RNTI for MTRP-eMBB and using them.In other words, when CRC masking of DCI is performed by using a RNTI forURLLC, UE considers it as URLLC transmission and when CRC masking of DCIis performed by using a RNTI for eMBB, UE considers it as eMBBtransmission. Alternatively, a base station may configure MTRP URLLCtransmission/reception or TRP eMBB transmission/reception to UE throughother new signaling.

In a description of the present disclosure, it is described by assumingcooperative transmission/reception between 2 TRPs for convenience of adescription, but a method proposed in the present disclosure may be alsoextended and applied in 3 or more multiple TRP environments and inaddition, it may be also extended and applied in multiple panelenvironments (i.e., by matching a TRP to a panel). In addition, adifferent TRP may be recognized as a different TCI state to UE.Accordingly, when UE receives/transmits data/DCI/UCI by using TCI state1, it means that data/DCI/UCI is received/transmitted from/to a TRP 1.

Hereinafter, methods proposed in the present disclosure may be utilizedin a situation that MTRPs cooperatively transmit a PDCCH (repetitivelytransmit or partitively transmit the same PDCCH). In addition, methodsproposed in the present disclosure may be also utilized in a situationthat MTRPs cooperatively transmit a PDSCH or cooperatively receive aPUSCH/a PUCCH.

In addition, in the present disclosure, when a plurality of basestations (i.e., MTRPs) repetitively transmit the same PDCCH, it may meanthe same DCI is transmitted through multiple PDCCH candidates and it mayalso mean that a plurality of base stations repetitively transmit thesame DCI. Here, the same DCI may mean two DCI with the same DCIformat/size/payload. Alternatively, although two DCI has a differentpayload, it may be considered the same DCI when a scheduling result isthe same. For example, a TDRA (time domain resource allocation) field ofDCI relatively determines a slot/symbol position of data and aslot/symbol position of A/N (ACK/NACK) based on a reception occasion ofDCI, so if DCI received at n occasions and DCI received at n+1 occasionsinform UE of the same scheduling result, a TDRA field of two DCI isdifferent and consequentially, a DCI payload is different. R, the numberof repetitions, may be directly indicated or mutually promised by a basestation to UE. Alternatively, although a payload of two DCI is differentand a scheduling result is not the same, it may be considered the sameDCI when a scheduling result of one DCI is a subset of a schedulingresult of the other DCI. For example, when the same data is repetitivelytransmitted N times through TDM, DCI 1 received before first dataindicates N data repetitions and DCI 2 received after first data andbefore second data indicates N−1 data repetitions. Scheduling data ofDCI 2 becomes a subset of scheduling data of DCI 1 and two DCI isscheduling for the same data, so in this case, it may be considered thesame DCI.

In addition, in the present disclosure, when a plurality of basestations (i.e., MTRPs) partitively transmit the same PDCCH, it meansthat one DCI is transmitted through one PDCCH candidate, but TRP 1transmits some resources that such a PDCCH candidate is defined and TRP2 transmits the remaining resources. For example, when a PDCCH candidatecorresponding to aggregation level m1+m2 is partitively transmitted byTRP 1 and TRP 2, a PDCCH candidate may be divided into PDCCH candidate 1corresponding to aggregation level m1 and PDCCH candidate 2corresponding to aggregation level m2, and TRP 1 may transmit PDCCHcandidate 1 and TRP 2 may transmit PDCCH candidate 2 to a differenttime/frequency resource. After receiving PDCCH candidate 1 and PDCCHcandidate 2, UE may generate a PDCCH candidate corresponding toaggregation level m1+m2 and try DCI decoding.

In addition, in the present disclosure, when UE repetitively transmitsthe same PUSCH so that a plurality of base stations (i.e., MTRPs) canreceive it, it may mean that UE transmitted the same data throughmultiple PUSCHs. In this case, each PUSCH may be optimized andtransmitted to an UL channel of a different TRP. For example, when UErepetitively transmits the same data through PUSCH 1 and 2, PUSCH 1 istransmitted by using UL TCI state 1 for TRP 1 and in this case, linkadaptation such as a precoder/MCS, etc. may be also scheduled/applied toa value optimized for a channel of TRP 1. PUSCH 2 is transmitted byusing UL TCI state 2 for TRP 2 and link adaptation such as aprecoder/MCS, etc. may be also scheduled/applied to a value optimizedfor a channel of TRP 2. In this case, PUSCH 1 and 2 which arerepetitively transmitted may be transmitted at a different time to beTDM, FDM or SDM.

In addition, in the present disclosure, when UE partitively transmitsthe same PUSCH so that a plurality of base stations (i.e., MTRPs) canreceive it, it may mean that UE transmits one data through one PUSCH,but it divides resources allocated to that PUSCH, optimizes them for anUL channel of a different TRP and transmits them. For example, when UEtransmits the same data through 10 symbol PUSCHs, data is transmitted byusing UL TCI state 1 for TRP 1 in 5 previous symbols and in this case,link adaptation such as a precoder/MCS, etc. may be alsoscheduled/applied to a value optimized for a channel of TRP 1. Theremaining data is transmitted by using UL TCI state 2 for TRP 2 in theremaining 5 symbols and in this case, link adaptation such as aprecoder/MCS, etc. may be also scheduled/applied to a value optimizedfor a channel of TRP 2. In the example, transmission for TRP 1 andtransmission for TRP 2 are TDM-ed by dividing one PUSCH into timeresources, but it may be transmitted by a FDM/SDM method.

In addition, similarly to the above-described PUSCH transmission, alsofor a PUCCH, UE may repetitively transmit the same PUCCH or maypartitively transmit the same PUCCH so that a plurality of base stations(i.e., MTRPs) receive it.

Hereinafter, a proposal of the present disclosure may be extended andapplied to a variety of channels such as a PUSCH/a PUCCH/a PDSCH/aPDCCH, etc.

A proposal of the present disclosure may be extended and applied to botha case in which various uplink/downlink channels are repetitivelytransmitted to a different time/frequency/space resource and a case inwhich various uplink/downlink channels are partitively transmitted to adifferent time/frequency/space resource.

Control Resource Set (CORESET)

A predetermined resource used for monitoring a downlink control channel(e.g., a PDCCH) may be defined based on a control channel element (CCE),a resource element group (REG) and a control resource set (CORESET). Inaddition, the predetermined resource may be defined as a resource whichis not used for a DMRS associated with a downlink control channel.

A CORESET corresponds to a time-frequency resource which tries decodingof a control channel candidate by using one or more search spaces (SS).For example, a CORESET is defined as a resource that a terminal mayreceive a PDCCH and a base station does not necessarily transmit a PDCCHin a CORESET.

In a time-frequency domain, a size and a position of a CORESET may beconfigured semi-statically by a network. In a time domain, a CORESET maybe positioned in any symbol in a slot. For example, a time length of aCORESET may be defined as up to 2 or 3 symbol durations. In a frequencydomain, a CORESET may be positioned at a position of any frequency in anactive bandwidth part (BWP) within a carrier bandwidth. A frequency sizeof a CORESET may be defined as a multiple of 6 RB units in a carrierbandwidth (e.g., 400 MHz) or less. A time-frequency position and size ofa CORESET may be configured by RRC signaling.

A first CORESET (or CORESET 0) may be configured by a master informationblock (MIB) provided through a PBCH. A MIB may be obtained by a terminalfrom a network at an initial access step and a terminal may monitor aPDCCH including information scheduling system information block1 (SIB1)in CORESET 0 configured by a MIB. After a terminal is configured forconnection, one or more CORESETs may be additionally configured throughRRC signaling. An identifier may be allocated to each of a plurality ofCORESETs. A plurality of CORESETs may be overlapped each other.

A PDSCH in a slot may be also positioned before starting or after endinga PDCCH in a CORESET. In addition, an unused CORESET resource may bereused for a PDSCH. For it, a reserved resource is defined, which may beoverlapped with a CORESET. For example, one or more reserved resourcecandidates may be configured and each of reserved resource candidatesmay be configured by a bitmap in a time resource unit and a bitmap in afrequency resource unit. Whether a configured reserved resourcecandidate is activated (or whether it may be used for a PDSCH) may bedynamically indicated or may be semi-statically configured through DCI.

One CCE-to-REG mapping relationship may be defined for each CORESET.Here, one REG is a unit corresponding to one OFDM symbol and one RB(i.e., 12 subcarriers). One CCE may correspond to 6 REGs. A CCE-to-REGmapping relationship of a different CORESET may be the same or may beconfigured differently. A mapping relationship may be defined in a unitof a REG bundle. A REG bundle may correspond to a set of REG(s) that aterminal assumes consistent precoding will be applied. CCE-to-REGmapping may include or may not include interleaving. For example, wheninterleaving is not applied, a REG bundle configured with 6 consecutiveREGs may form one CCE. When interleaving is applied, a size of a REGbundle may be 2 or 6 when a time duration length of a CORESET is 1 or 2OFDM symbols and a size of a REG bundle may be 3 or 6 when a timeduration length of a CORESET is 3 OFDM symbols. A block interleaver maybe applied so that a different REG bundle will be dispersed in afrequency domain and mapped to a CCE. The number of rows of a blockinterleaver may be variably configured for a variety of frequencydiversities.

In order for a terminal to receive a PDCCH, channel estimation using aPDCCH DMRS may be performed. A PDCCH may use one antenna port (e.g.,antenna port index 2000). A PDCCH DMRS sequence is generated across theentire common resource block in a frequency domain, but it may betransmitted only in a resource block that an associated PDCCH istransmitted. Meanwhile, before a terminal obtains system information inan initial access process, a position of a common resource block may notbe known, so for CORESET 0 configured by a MIB provided through a PBCH,a PDCCH DMRS sequence may be generated from a first resource block ofCORESET 0. A PDCCH DMRS may be mapped to every fourth subcarrier in aREG. A terminal may perform channel estimation in a unit of a REG bundleby using a PDCCH DMRS.

Search Space (SS)

DCI in various formats or in various sizes may be used in PDCCHtransmission and a terminal may perform blind detection or blinddecoding for DCI by monitoring a PDCCH candidate based on apredetermined DCI format. A different DCI format may not necessarilyhave a different DCI size. Search space (SS) may be defined to limit thenumber of PDCCH candidates which should be monitored by a terminal.

Search space may be a set of control channel candidates corresponding toCCE(s) according to a predetermined aggregation level. For example, anaggregation level may be defined as 1, 2, 4, 8 or 16 and a PDCCH may beconfigured with a set of CCE(s) corresponding to an aggregation level.One or more CORESETs may be configured for a terminal and one or moresearch space may be configured for each CORESET. The number of PDCCHcandidates may be configured per search space or per aggregation level.

Search space may include terminal-specific search space and commonsearch space shared by multiple terminals. In terminal-specific searchspace, a terminal may try decoding of a PDCCH candidate based on aterminal-specific identifier (e.g., a C-RNTI). In common search space, aterminal may try decoding of a PDCCH candidate based on an identifierfor a specific purpose (e.g., a SI (System Information)-RNTI, a P(Paging)-RNTI, a RA (Random Access)-RNTI, etc.), not a uniqueidentifier. A CCE set for common search space may be predefined.

A terminal may try decoding of a PDCCH candidate for correspondingsearch space at a monitoring occasion (MO) configured for search space.In trying decoding of a PDCCH candidate, a terminal may processinformation transmitted through a PDCCH when it succeeds in CRC checkbased on an available RNTI, and it may ignore it by determining that itis information which is intended by other terminal or that an errorexists when it fails in CRC check.

One search space (SS) may correspond to one monitoring occasion (MO) andone search space set (SS set) may correspond to a set of MOs. Inaddition, one SS set may define a time position that a CORESETassociated with it exists (e.g., a period and/or an offset). In otherwords, a terminal may perform blind decoding for a PDCCH in a CORESETexisting based on a period/an offset corresponding to a SS set. Forexample, MO 1 may exist repetitively in a period corresponding to SS set1 and MO 2 may exist repetitively in a period corresponding to SS set 2.In addition, one CORESET may be associated with one or more (e.g., up to10) SS sets, but one SS set may be associated only with one CORESET.

In addition, a CORESET is defined as a predetermined time-frequencyresource in one time unit (e.g., a slot) and a space parameter (e.g., aTCI state, or a QCL RS) may be configured for each CORESET.

In addition, in relation to a blind decoding (BD) for a downlink controlchannel (e.g., PDCCH), an upper limit or a budget for at least one ofthe number of BDs or the number of CCEs (or the number of aggregatedCCEs) in a predetermined time unit (e.g., one slot) may be configured.Such upper limit/budget may be related to the capability (e.g.,processing speed) of the terminal. When the number of BD/CCE counted bythe terminal within a predetermined time unit exceeds the upper limit,some SS set may be dropped. That is, the terminal may not attempt PDCCHmonitoring/detection/blind decoding in the CORESET corresponding to thesome SS set within the predetermined time unit.

Transmission/Reception Based on a Group of Time Units

The present disclosure includes examples of transmission and receptionoperations based on a group of existing time units (e.g., symbols,slots, etc.) (hereinafter, a group of time units) in a system supportinga subcarrier spacing (SCS) larger than the existing SCS.

For example, NR system currently defines an operation based on SCS(e.g., 15 kHz, 30 kHz, 60 kHz, 120 kHz) in a band of 52.6 GHz or less.For the future NR system (e.g., high frequency (HF)-NR) operating in alicensed and/or unlicensed band of 60 or 70 GHz frequency band (e.g.,higher than 52.6 GHz to 71 GHz), it is being discussed to supportoperation in a higher frequency and wider bandwidth compared to theexisting NR system. Considering the radio channel characteristics in thehigh frequency band, such as larger phase noise and larger Dopplershift, introduction and application of new OFDM numerology based on theSCS (e.g., 240 kHz, 480 kHz, 960 kHz, . . . ) larger than the existingNR SCS may be required.

As described with reference to FIG. 4 , as the SCS in the frequencydomain increases, the OFDM symbol length/duration in the time domain maybe shortened. For example, in the case of 960 kHz SCS, the length of oneOFDM symbol period including the CP may be approximately 1.1 μsec, andthe length of one slot composed of 14 OFDM symbols may be approximately15.6 μsec.

More specifically, in the existing NR system, the mmWave band (e.g.,higher than 7.125 or 24 MHz, up to 52.6 GHz) is defined as FR2, and theSCS for the SS/PBCH block in the corresponding band may be either of 120or 240 kHz, and the SCS for other signals/channels (e.g., PDCCH, PDSCH,PUSCH, etc.) may be either 60 or 120 kHz.

Assuming that the scalability of the OFDM symbol duration and CP lengthdefined in the existing NR system is maintained for a SCS larger thanthe existing SCS, the OFDM symbol duration and CP length for each SCSmay be applied as shown in Table 6.

TABLE 6 SCS [kHz] 120 240 480 960 Symbol duration 8.33 μs 4.17 μs 2.08μs 1.04 μs CP length 586 ns 293 ns 146 ns 73 ns

In addition, in the existing NR system, a period of a search space (SS)set capable of configuring a monitoring occasion (MO) for a downlinkcontrol channel (e.g., PDCCH) is defined as at least one slot. As thelength of a slot becomes shorter due to the introduction of a large SCS,a higher processing speed, higher power consumption, higherimplementation complexity, or the like may be required for the terminalto monitor the downlink control channel for every slot.

In the present disclosure, in order to alleviate the burden of downlinkcontrol channel monitoring of the terminal in a system supporting alarge SCS, a new transmission/reception operation based on a group oftime units will be described. In addition, examples related to downlinkcontrol channel monitoring/decoding/reception and examples related touplink/downlink transmission/reception related to timing of a downlinkcontrol channel, based on a transmission/reception operation based on agroup of time units, will be described.

In the present disclosure, the values for the criteria for classifyingfrequency bands, SCS, and the length of time units are merely exemplary,and the scope of the present disclosure includes applying the followingexamples to a case in which a relatively large SCS compared to theexisting SCS in any frequency band is applied, and accordingly, arelatively short time unit length is applied.

In the present disclosure, a plurality (i.e., M, where M is an integergreater than 1) of time units are defined as one group of time units.

For example, M time units may include contiguous or consecutive timeunits. Contiguous or consecutive time units include as case where, ifthere is other time domain element between the time units, target timeunits excluding the other time domain element are continuous, as well asa continuous case where there is no other time domain element betweenthe time units. For example, if other time domain element exists betweensome time units, indexes are sequentially assigned only to target timeunits, and time units having continuous indexes may be referred to ascontiguous/consecutive time units.

In the examples of the present disclosure, for clarity of explanation,it is described assuming that one time unit is one slot, and the groupof time units is a slot group (i.e., a set of (contiguous/consecutive) Mslots). However, the scope of the present disclosure is not limited tothe case where one time unit is one slot, and the following examples maybe applied to cases where one time unit is one symbol, a symbol group(or span), a mini slot, a subframe, a subframe group, a half frame, aframe, or the like.

As a representative example of the present disclosure, M slots may bedefined as one slot group, and downlink control channel monitoring in aslot group unit (or based on a slot group) may be configured andperformed. In the following example, it is assumed that the downlinkcontrol channel is a PDCCH, but examples of the present disclosure maybe applied to other (or not yet defined) downlink channels to which theblind decoding method is applied.

In addition, a plurality of slot groups do not overlap each other andmay be configured or defined as consecutive.

The M value may have a value of 2^(n) (where n is an integer greaterthan or equal to 1) to facilitate alignment with respect to differentSCSs. For example, if M=8 is configured for active DL BWP operating at960 kHz SCS, 8 slots of the active DL BWP are configured as one slotgroup, and the corresponding slot group may correspond to one slot inthe case of 120 (=960/M) kHz SCS.

Alternatively, a reference SCS (ref-SCS) value may be configured. If theref-SCS value is configured as 120 kHz for an active DL BWP operatingwith 960 kHz SCS, this may mean that 8 slots in the 960 kHz SCScorresponding to 1 slot based on 120 kHz SCS are configured as one slotgroup. In this case, it may be that M=(2^(μ-bwp)/2^(μ-ref)). Here, μ-refrepresents the configuration index of ref-SCS (e.g., μ-ref=3 in case of120 kHz SCS), and μ-bwp represents the SCS configuration index of anactive DL BWP (e.g., μ-bwp=6 in case of 960 kHz SCS). Here, therelationship between u that is the SCS index and SCS is SCS=15*2^(μ)(see Table 1). For example, it may be defined in addition to the Table1, μ=5 corresponds to 480 kHz SCS, and μ=6 corresponds to 960 kHz SCS.

The base station may provide configuration information for the slotgroup to the terminal. For example, the configuration information mayinclude at least one of M, n(=log₂ M), ref-SCS, or ref-SCS configurationindex. As described above, M is the number of slots included in one slotgroup, n is the number of powers of two corresponding to the number ofslots, and ref-SCS may indirectly indicate the number of slots throughthe relationship with the SCS of the corresponding BWP. The terminal mayrecognize/determine the number of slots included in one slot group basedon the configuration information.

Additionally or alternatively, information on the number of slotsincluded in one slot group may be predefined for each SCS, given as afixed value, or determined according to a capability value reported bythe terminal to the base station, and the terminal may know thecorresponding value without separate signaling from the base station.

Additionally or alternatively, information on the number of slotsincluded in one slot group may be implicitly signaled to the terminal,from other signaling information (e.g., a period value of the SS set)from the base station.

In addition, a default M value to be assumed by the terminal may bedefined before the M value is configured for an initial access terminalor an active DL BWP. Specifically, the default M value may be predefinedas 1, or derived based on a specific ref-SCS (e.g., 120 kHz SCS). Forexample, the default M value may be derived by (2^(μ-bwp)/2^(μ-ref)). Asa further example, a default M value may be defined/derived based onlyon the μ-bwp value. For example, the default M value may bedefined/derived based on the μ-bwp value, regardless of ref-SCS (orwithout configuration/indication of ref-SCS, or assuming a fixed ref-SCSvalue). For example, if μ-bwp=5, the default M value may be 4, and ifμ-bwp=6, the default M value may be 8.

In addition, for the same SCS, supportable M values may be differentfrom each other according to the capability of each terminal. Forexample, if the terminal informs the base station that it can supportthe value M_1 as terminal capability information, the terminal mayexpect that the M value configured by the base station is greater thanM_1. Additionally or alternatively, the terminal may expect that theminimum configuration unit (or unit size (granularity)) of the timedomain characteristics (e.g., at least one of period, offset, orduration) of the SS set is configured as M_1 or higher, or a multiple ofM_1.

In addition, the terminal may inform the base station that a pluralityof M values can be supported for a specific serving cell (or DL BWP orSCS) as terminal capability information. The terminal mayestimate/determine an M value to be actually applied among a pluralityof M values based on a parameter for time domain characteristics of anSS set configured for a corresponding serving cell (or DL BWP or SCS).For example, it may be determined that the maximum M value smaller thanthe minimum among the period values of the SS set configured for theserving cell (or DL BWP or SCS) is the M value to be applied to thecorresponding serving cell (or DL BWP or SCS). For example, a terminalreporting two values of M_1=4 and M_2=16 as capabilities for a specificDL BWP, if the minimum period value of the SS sets of the correspondingDL BWP is 8 slots, may know that the M value is 4 for the correspondingDL BWP. Accordingly, the terminal may perform PDCCH monitoring based ona slot group including 4 slots.

In the examples of the present disclosure, for clarity, followingdescription is based on one value of M, n, ref-SCS, and ref-SCSconfiguration index, but for a case that the number of slots included inone slot group is determined based on another value, examples of thepresent disclosure may be analogously applied. DL BWP or active DL BWPdescribed in the present disclosure may be replaced with terms such as aserving cell and a downlink carrier.

In the present disclosure, it may be applied to a system operating in aspecific frequency range (e.g., an FR (e.g., 52.6 GHz to 71 GHz)distinct from existing FR1 and FR2), and/or DL BWP applied with aspecific SCS (e.g., 120 kHz) or higher. In the following description,for clarity, the specific frequency range may be referred to as FR2-2(in this case, the existing FR2 (i.e., 24250 MHz-52600 MHz) may bereferred to as FR2-1) or FR3, and it may be assumed a case where FR2-2or FR3 is applied. However, the scope of the present disclosure is notlimited to the names FR2-2 or FR3, and may be understood to includeexamples in which the specific frequency range is applied or an SCSequal to or higher than the specific SCS is applied.

Examples of the present disclosure may be defined in integration withexisting operations. For example, the operation may be defined based onN (i.e., the number of slots included in one slot group) regardless ofthe frequency range/SCS, and N=1 may be configured/defined for FR1/FR2(and/or a specific SCS (e.g., 120 kHz) or lower), and N>1 may beconfigured/defined for FR3 (and/or higher than a specific SCS (e.g., 120kHz)).

In the following examples, being configured with or given the M valuemay be interpreted as a case where N>1 (i.e., a case where one slotgroup includes a plurality of slots). Not being configured with or giventhe M value mat be interpreted as a case where N=1 (i.e., a case wherethe slot group is not configured).

FIG. 7 is a diagram for explaining a method of transmitting or receivingby a terminal based on a group of time units according to an embodimentof the present disclosure.

In step S710, the terminal may receive configuration information for aslot group from the base station.

The configuration information may include information on M (M is aninteger greater than 1) which is the granularity of the slot group. Forexample, M may correspond to the number of slots included in one slotgroup. Here, one slot may have a length based on a specific SCSconfigured for a BWP/cell/carrier in which the terminal operates (e.g.,performing PDCCH monitoring). Also, a slot group may be configured forat least one of an SCS higher than a predetermined SCS, or apredetermined frequency range. As an additional example, theconfiguration information may include at least one of an M value, ann(=log₂ M) value, or information on a ratio between a reference SCS anda specific SCS.

If the terminal performs monitoring of a downlink control channel (e.g.,PDCCH) before receiving the configuration information for the slot groupin S710, for the BWP/cell/carrier in which the terminal operates adefault M value previously configured/defined (e.g., based on a specificSCS) may be applied.

In step S720, the terminal may monitor a downlink control channel in atleast one search space (SS) set.

The time domain characteristics (e.g., at least one of period, offset,or duration) of the SS set may be configured based on M which is agranularity of the slot group. For example, at least one of the periodor offset of the SS set may be configured to be greater than or equal tothe M-slot length or a multiple of the M-slot length. For example, theduration of the SS set may be configured to be one of a value less thanor equal to the M-slot length, a value less than or equal to a multipleof the M-slot length, or a value less than or equal to the product ofthe M value and the length of the period of the slot-based SS set.

Regarding SS set monitoring, at least one of the number of PDCCHcandidates and/or the number of non-overlapping CCEs may be counted ineach slot group (i.e., in units of slot groups). In addition, themaximum number of PDCCH candidates and/or the maximum number ofnon-overlapping CCEs (i.e. BD/CCE upper limit/budget) may be configuredin each slot group (i.e., in units of slot groups). SS sets exceedingthe BD/CCE upper limit/budget in each slot group may not be monitored ormay be dropped. SS sets that are not monitored or dropped may bedetermined sequentially according to the order of indices of a pluralityof SS sets.

When a plurality of cells are configured for the terminal (i.e., in caseof carrier aggregation (CA)), the BD/CCE upper limit/budget may bedistributed among the plurality of cells in units of slot groups. Also,for a primary cell (PCell) among a plurality of cells, whether tomonitor or drop an SS set may be determined in each slot group. Forexample, whether to monitor or drop the SS set may be determined in thefirst N (N is an integer of 1 or greater) slots among the M slotsincluded in the slot group.

In addition, if any one SS set is not included in one slot group (or ifone SS set appears across multiple slot groups (e.g., consecutive slotgroups)), the SS sets may not be monitored or may be dropped.

When a terminal reports capability information for a slot groupgranularity supported by the terminal to the base station, the M valueconfigured by the base station may be configured as a value greater thanor equal to the slot group granularity reported by the terminal. When aterminal has a plurality of supported slot group granularities andreports them to the base station as capability information, the M valuemay be determined based on the time domain characteristic value of theSS set.

In step S730, the terminal may receive downlink control information(DCI) on the downlink control channel.

When SS set group switching is triggered for the terminal, monitoringmay be performed on the switched SS set group from the first slot groupafter a predetermined length of time (e.g., P symbols) from thetimepoint of triggering. In addition, a timer related to the trigger ofSS set group switching may decrease by 1 for each slot group.

In addition, a predetermined time interval indicated through DCI (e.g.,a time interval between a downlink allocation DCI reception and acorresponding PDSCH reception, a time interval between a downlink datareception and a corresponding HARQ-ACK transmission, a time intervalbetween uplink grant DCI reception and a corresponding PUSCHtransmission, or the like) may be applied based on units of slot groups.

FIG. 8 is a diagram for explaining a method of transmitting or receivingby a base station based on a group of time units according to anembodiment of the present disclosure.

In step S810, the base station may transmit configuration informationfor the slot group to the terminal.

Description of the configuration information for the slot group is thesame as that of step S710, a duplicate description is omitted.

Before the configuration information for the slot group is transmittedto the terminal, when the terminal performs SS set monitoring, the basestation expects the terminal to operate based on a previouslyconfigured/defined default M value, or such restrictions may be appliedto the base station.

In step S820, the base station may transmit a downlink control channelincluding downlink control information (DCI) to the terminal in at leastone search space (SS) set.

When the base station configures the time domain characteristics (e.g.,at least one of period, offset, or duration) of the SS set, restrictionsfor such configuration to be based on the slot group granularity M maybe applied. For example, at least one of the period or offset of the SSset may be configured as a length greater than or equal to the M-slotlength or a multiple of the M-slot length. For example, the duration ofthe SS set may be configured as one of a value less than or equal to theM-slot length, a value less than or equal to a multiple of the M-slotlength, or a value less than or equal to the product of the M value andthe length of the period of the slot-based SS set.

The base station may transmit a PDCCH in an SS set exceeding the maximumnumber of PDCCH candidates and/or the maximum number of non-overlappingCCEs (i.e., BD/CCE upper limit/budget) of the terminal, but the basestation may expect that SS sets exceeding the BD/CCE upper limit/budgetin each slot group, or an SS set not completely included in one slotgroup (or an SS set having period/duration across multiple slot groups)may not be monitored or may be dropped by the terminal, or suchrestrictions may be applied to the base station.

When a plurality of cells are configured for the terminal (i.e., in caseof carrier aggregation (CA)), the base station may expect that theBD/CCE upper limit/budget is distributed among the plurality of cells inunits of slot groups, or such restrictions may be applied to the basestation. Also, for a primary cell (PCell) among a plurality of cells,the base station may expect that whether to monitor or drop an SS set isdetermined in each slot group, or such restrictions may be applied tothe base station. For example, the base station may expect that whetherto monitor or drop the SS set is determined in the first N (N is aninteger of 1 or greater) slots among the M slots included in the slotgroup, or such restrictions may be applied to the base station.

When a terminal reports capability information for a slot groupgranularity supported by the terminal to the base station, restrictionsfor the base station to configure the M value to a value greater than orequal to the slot group granularity reported by the terminal may beapplied. When a terminal has a plurality of supported slot groupgranularities and reports them to the base station as capabilityinformation, the M value may not be explicitly signaled by the basestation, but may be implicitly indicated to the terminal based on thetime domain characteristic value of the SS set.

When SS set group switching is triggered for the terminal, the basestation may expect that the terminal performs monitoring on the switchedSS set group from the first slot group after a predetermined length oftime (e.g., P symbols) from the timepoint of triggering, or suchrestrictions may be applied to the base station. In addition, the basestation may expect that a timer related to the trigger of SS set groupswitching decreases by 1 for each slot group, or such restrictions maybe applied to the base station.

In addition, the base station may expect that a predetermined timeinterval indicated through DCI (e.g., a time interval between a downlinkallocation DCI reception and a corresponding PDSCH reception, a timeinterval between a downlink data reception and a corresponding HARQ-ACKtransmission, a time interval between uplink grant DCI reception and acorresponding PUSCH transmission, or the like) is applied based on unitsof slot groups, or such restrictions may be applied to the base station.

Hereinafter, specific examples of the present disclosure fortransmission or reception based on a group of time units will bedescribed.

Embodiment 1

The present embodiment relates to, based on the configuration of thenumber (M) of slots included in one slot group, an example that the timedomain characteristic of the SS set is configured based on a granularityof the slot group (hereinafter referred to as “M-slot”). That is, M-slotmay mean a time length corresponding to M slots.

For example, for an active DL BWP for which a value M isconfigured/given, the period and/or offset value of the SS set may beconfigured to be greater than or equal to M-slot or a multiple ofM-slot. Additionally or alternatively, for the active DL BWP for whichthe M value is configured, the duration value of the SS set may beconfigured to be less than or equal to M-slot, less than or equal to amultiple of M-slot, or less than or equal to period of the SS set*M.Here, the duration of the SS set being configured to be less than orequal to the period of the SS set*M may correspond to a case that theperiod of the SS set is signaled in slot-based granularity (as in theexisting scheme) and the duration of the SS set is signaled as a valueless than or equal to the period, and the period of the SS set isapplied as the signaled period*M and the duration of the SS set isapplied as the signaled duration*M according to the interpretation ofthe terminal.

Alternatively, the period of SS set may be configured as a shorterlength than M-slot. In addition, the duration of the SS set may beconfigured as a shorter length than the period of the SS set.

For example, the period and/or offset value of the SS set may beconfigured based on a higher layer signaling parametermonitoringSlotPeriodAndOffset. The duration of the SS set may beconfigured based on a higher layer signaling parameter duration, and theduration value of the SS set may be configured as a value equal to orless than the period of the SS set.

As such, information on a time domain occasion (or monitoring occasion)for PDCCH monitoring, such as a period, offset, and duration of the SSset, may be configured in the SS set configuration. According to thepresent disclosure, when a slot group including a plurality of slots isconfigured (or M value is configured), configuration of the time domaincharacteristics of the SS set may be configured based on M-slotgranularity instead of the existing slot granularity. Accordingly,sufficient time for the terminal to perform monitoring and processing ofPDCCH may be secured, so that advantageous effects such as powerconsumption reduction and implementation complexity simplification maybe achieved.

For example, in the existing SS set configuration, the period may bedefined as ks slots. If the value of M may be configured (for example,if FR3 is supported), a parameter called ks′ instead of ks may bedefined, it may be defined that ks′=ks for FR1 and FR2, and ks′=ks*M forFR3. Alternatively, it may be defined as ks slot groups (i.e., ksM-slots) instead of ks slots may be defined.

FIG. 9 is a diagram illustrating a downlink control channel monitoringopportunity based on a group of time units according to an embodiment ofthe present disclosure.

In the example of FIG. 9(a), it illustrates a case in which the M valueis configured as 4 for the active DL BWP operating in 480 kHz SCS. Inthis case, the period of the SS set may be configured as 4-slot (orslots of multiple of 4). Therefore, PDCCH monitoring may be performedevery 4 slots instead of every slot.

As an additional example, the time domain characteristics (e.g., atleast one of period, offset, or duration) of the SS set when the M valueis configured may be interpreted assuming a case of ref-SCS. Forexample, if the monitoring occasion (MO) exists in the n-th slot or slotindex #n (hereinafter referred to as slot #n) assuming the case ofref-SCS, it may be interpreted that, among slots #m, #m+1, #m+2, . . .of a target SCS (e.g., SCS greater than ref-SCS) facing or correspondingto slot #n of ref-SCS, MO of the target SCS is present in a specificslot (e.g., an earliest slot).

Referring to FIG. 9(b), it is assumed that ref-SCS is configured as 120kHz for active DL BWP operating with 480 kHz SCS. For example, in SS setconfiguration based on ref-SCS, it may be configured as period=2 slots,offset=0, duration=1 slot, and CORESET position in symbol #0/#7 in theslot. In this case, the terminal may assume that corresponding SS setsare configured in slot #0 and slot #2 based on 120 kHz SCS. It may beseen that, among slots #0, #1, #2, and #3 based on 480 kHz SCS whichface slot #0 based on the ref-SCS of 120 kHz SCS, MO presents in symbol#0/#7 in the earliest slot #0. Also, it may be seen that, among slots#8, #9, #10, and #11 based on 480 kHz SCS which face slot #2 based onthe ref-SCS of 120 kHz SCS, MO presents in symbol #0/#7 in the earliestslot #8.

Embodiment 2

The present embodiment relates to a method of applying a BD/CCE countrelated to PDCCH monitoring and an upper limit/budget thereto in unitsof slot groups (i.e., M-slots).

For example, in calculating the maximum number of PDCCH candidatesand/or the maximum number of non-overlapped CCEs for DL BWP, it may bereported/determined in units of M-slots.

When a slot group is not applied (i.e., when M value is not configuredas in the existing scheme), the maximum number of PDCCH candidatesmonitored per serving cell and per slot may be defined based on the SCSconfiguration index μ. For example, for μ=0, 1, 2, and 3, the maximumnumber of PDCCH candidates (M_(PDCCH) ^(max,slot,μ)) may be defined as44, 36, 22, and 20, respectively.

In addition, when the slot group is not applied (i.e., when the M valueis not configured as in the existing scheme), the maximum number ofnon-overlapping CCEs per serving cell and per slot may be defined basedon the SCS configuration index μ. For example, for μ=0, 1, 2, and 3, themaximum number of CCEs (C_(PDCCH) ^(max,slot,μ)) may be defined as 56,56, 48, and 32, respectively.

For a DL BWP to which a slot group is applied (i.e., M value isconfigured), PDCCH monitoring may be performed in a period based on aslot group (i.e., M-slot) unit instead of a slot unit. Accordingly, themaximum number of PDCCH candidates and/or the maximum number ofnon-overlapping CCEs for the corresponding DL BWP may be defined inunits of slot groups.

For example, for a DL BWP configured with the SCS configuration indexμ_1, if an SCS configuration index corresponding to the M value (orcorresponding to ref-SCS) is μ_2 (i.e., 2^(μ_1)/2^(μ_2)=M), the maximumnumber of PDCCH candidates and the maximum number of non-overlappingCCEs defined for the configuration index μ_2 may be applied in units ofslot groups to the corresponding DL BWP.

For example, as shown in Table 7, the maximum number of PDCCH candidatesmonitored per serving cell and per slot (M_(PDCCH) ^(max,slot,μ)) may bepredefined.

TABLE 7 maximum number of PDCCH candidates μ monitored per serving celland per slot 0 44 1 36 2 22 3 20 4 P1 5 P2 6 P3 . . . . . .

When M=4 is configured for DL BWP operating in 480 kHz SCS (i.e., μ=5),the maximum number of PDCCH candidates monitored “per slot group”including 4 slots may be 20. Specifically, regardless of the P2 value ofTable 7 (i.e., the maximum number of PDCCH candidates “per slot”), itmay be determined that 20 which is the maximum number of PDCCHcandidates “per slot” defined based on 480/M=480/4=120 kHz SCS (i.e.,μ=3) is the maximum number of PDCCH candidates “per slot group” based on480 kHz SCS (i.e. μ=5).

Embodiment 2-1

A case in which carrier aggregation (CA) is configured for a terminalwill be described.

When CA of a plurality of DL cells is configured for the terminal, in acase that a predetermined condition is satisfied, the maximum number ofPDCCH candidates and the maximum number of non-overlapping CCEs may bedistributed based on the SCS of the DL BWP in each serving cell.

For example, the predetermined condition may be expressed as Equation 3.

$\begin{matrix}{{\sum\limits_{\mu = 0}^{3}N_{cells}^{{DL},\mu}} > N_{cells}^{cap}} & \left\lbrack {{Equation}3} \right\rbrack\end{matrix}$

In Equation 3, N_(cells) ^(DL,μ) corresponds to the number of DL cellsfor which the SCS configuration index μ is configured. N_(cells) ^(cap)may be configured as the BD/CCE capability value of the terminal.

When the condition of Equation 3 is satisfied, the terminal may notmonitor (or may drop) a PDCCH candidate exceeding the value of Equation4 or a non-overlapping CCE exceeding the value of Equation 5 per slot.

$\begin{matrix}{M_{PDCCH}^{{total},{slot},\mu} = \left\lfloor {{N_{cells}^{cap} \cdot M_{PDCCH}^{\max,{slot},\mu} \cdot N_{cells}^{{DL},\mu}}/{\sum\limits_{j = 0}^{3}N_{cells}^{{DL},j}}} \right\rfloor} & \left\lbrack {{Equation}4} \right\rbrack\end{matrix}$ $\begin{matrix}{C_{PDCCH}^{{total},{slot},\mu} = \left\lfloor {{N_{cells}^{cap} \cdot C_{PDCCH}^{\max,{slot},\mu} \cdot N_{cells}^{{DL},\mu}}/{\sum\limits_{j = 0}^{3}N_{cells}^{{DL},j}}} \right\rfloor} & \left\lbrack {{Equation}5} \right\rbrack\end{matrix}$

In Equations 4 and 5, M_(PDCCH) ^(total,slot,μ) is the number of PDCCHcandidates that can be monitored, and C_(PDCCH) ^(total,slot,μ) is thenumber of non-overlapping CCEs that can be monitored.

In Equations 3 to 5, it is assumed that the SCS configuration index μ is0 to 3, but the scope of the present disclosure includes the case wherethe SCS configuration index μ is 4 or higher (see Table 7).

As described above, for the DL BWP configured as the SCS configurationindex μ_1, if a configuration index of the SCS corresponding to the Mvalue (or corresponding to the ref-SCS) is μ_2 (i.e.,2^(μ_1)/2^(μ_2)=M), the maximum number of PDCCH candidates and themaximum number of non-overlapping CCEs defined for the SCS configurationindex μ_2 may be applied in units of slot groups to the corresponding DLBWP.

Here, in Equations 4 and 5 for distributing the maximum number of PDCCHcandidates and/or the maximum number of non-overlapping CCEs, the valueof j in N_(cells) ^(DL,j) may be applied as a value corresponding toμ_2, not μ_1. That is, when the M value is configured for the terminal,it may be assumed not the SCS value of the DL BWP to which the M valueis applied, but the SCS value in which one slot having a lengthcorresponding to one slot group is configured. In other words, since thedistribution according to Equations 4 and 5 is based on the maximumnumber of PDCCH candidates and/or the number of non-overlapping CCEs“per slot,” Equation 4 and 5 may be applied based on the SCS having theslot corresponding to the “slot group.”

For example, if the SCS value of the DL BWP to which the M value isapplied is 480 kHz (i.e., μ_1=5) and M=4, based on an SCS value of 120kHz (i.e., μ_2=3) which configures a slot having a length correspondingto one slot group (i.e. 4-slot), the distribution equations of Equations4 and 5 may be applied (i.e., the value of j in N_(cells) ^(DL,j) inEquations 4 and 5 is not 5 but 3). That is, it may be expressed asj=μ_2=μ_1−log₂ M.

Embodiment 2-2

In case that the number of PDCCH candidates (and/or the number ofnon-overlapping CCEs) per slot for the primary cell (PCell) exceeds themaximum number of allowed PDCCH candidates (and/or the maximum number ofnon-overlapping CCEs), the terminal may drop a specific SS set in thecorresponding slot and may not monitor it.

Such an SS set drop may be applied for each slot group corresponding tothe M-slot for a DL BWP to which an M value is given.

Additionally or alternatively, the SS set drop may be applied per slotfor a DL BWP given a value M, and in this case, SS set drop may beperformed only for the first N slots in a slot group (e.g., the N valuemay be predefined or signaled by a base station, for example, N-2). Inother words, the terminal may expect that, in slot(s) other than thefirst N slots in the slot group, the number of PDCCH candidates (and/orthe number of non-overlapping CCEs) does not exceeds the allowed maximumnumber of PDCCH candidates (and/or the maximum number of non-overlappingCCEs). Accordingly, the terminal may not determine (or the terminal mayskip determining), for slots other than the first N slots in the slotgroup (and/or the number of non-overlapping CCEs), whether the number ofPDCCH candidates (and/or the number of non-overlapping CCEs) exceeds theallowed maximum number of PDCCH candidates (and/or the maximum number ofnon-overlapping CCEs).

When a plurality of SS sets exist in one slot group, SS sets to bedropped may be determined sequentially according to the order of indicesof the plurality of SS sets.

Embodiment 3

The present embodiment an example relates to the PDCCH monitoringoperation for a case that the period and/or duration of the SS set isnot included in one slot group (i.e., M-slot) (or one SS set existsacross a plurality of (consecutive) slot groups).

For example, for an active DL BWP to which a value M is configured, aperiod and/or duration corresponding to a specific SS set may not beincluded in one slot group (i.e., M-slot). For example, when the SS setis repeated according to a configured period, the n-th SS set periodand/or the n-th SS set duration are not included in one slot group(i.e., M-slot), and across a plurality of (adjacent) slot groups (i.e.,M-slots). Here, the SS set monitoring may not be performed (e.g.,monitoring off) during a specific interval (e.g., SS setperiod/duration) that is not completely included in one slot group(i.e., M-slot), and if SS set drop is required due to exceeding BD/CCEupper limit/budget, a specific interval not included in one slot group(i.e., M-slot) among the corresponding SS set may be dropped first.

Referring to FIG. 9(c), when the active DL BWP with M=4 is configuredwith 480 kHz SCS, a period of 3 slots may be configured for the SS set.MOs corresponding to period #1 and period #4 included in one slot groupincluding of 4-slots may be considered valid, and MOs (e.g., slots #3and #6) corresponding to period #2 and period #3 not included in oneslot group may be considered invalid. In invalid MO(s), PDCCH monitoringof the terminal may not be required or the terminal may omit/skip PDCCHmonitoring.

As an additional example, in performing SS set drop based on the maximumnumber of PDCCH candidates and/or the maximum number of non-overlappingCCEs per slot group (i.e., M-slot), it may be assumed that SS set #nneeds to be dropped for a specific slot group (i.e., a first slot groupcorresponding to slots #0, #1, #2, and #3). In this case, instead ofdropping the entire SS set #n, if an SS set corresponding to period #2that is not included in one slot group (e.g., a first slot groupcorresponding to slots #0, #1, #2, and #3, or a second slot groupcorresponding to slots #4, #5 , #6, and #7) is dropped first, it may bedetermined whether conditions for the maximum number of PDCCH candidatesand/or the maximum number of non-overlapping CCEs are satisfied. Ifsatisfied, the SS set corresponding to period #2 may be dropped first,and PDCCH monitoring corresponding to period #1 may be performed. If notsatisfied, whether to drop the SS set corresponding to period #1included in one slot group may be additionally determined.

As an additional example, in performing SS set drop based on the maximumnumber of PDCCH candidates and/or the maximum number of non-overlappingCCEs per slot group (i.e., M-slot), it may be counted except for thenumber of PDCCH candidates and the number of CCEs of the SS setcorresponding to period #2 and/or period #3 not included in one slotgroup.

As described above, the BD/CCE upper limit/budget calculation of theterminal may be applied in units of slot groups, and the time domaincharacteristics such as period/offset/duration of the PDCCH MO/SS setmay be configured differently from the granularity of one slot group.For example, the time domain characteristics of the SS set may beconfigured to be smaller than M-slot, equal to or larger than M-slot, ormultiple of M-slot.

Embodiment 4

The present embodiment relates to a method of performing SS set groupswitching based on a slot group.

For example, it is assumed that an SS set group (i.e., a group includingat least one SS set) is configured for an active DL BWP to which a valueM is configured, and SS set group switching is performed. In this case,the timing at which monitoring of group index #x is stopped andmonitoring of group index #y is started may be determined based on aslot group granularity boundary (i.e., a boundary between M-slots).

As an additional example, the value of a timer related to SS set groupswitching (e.g., a timer configured based on thesearchSpaceSwitchingTimer parameter) may be decreased by 1 per slotgroup granularity (e.g., M-slot).

For example, when the M value is not configured (i.e., the slot group isnot configured), the terminal may start PDCCH monitoring in the SSset(s) corresponding to the switched group index, from the first “slot”after at least a predetermined number (e.g., P_switch) of symbol(s) fromthe time point when SS set group switching is triggered.

The time point at which SS set group switching is triggered is, forexample, a time point at which an SS set switching flag is indicated byDCI format 2_0, a predetermined timer value expires, receiving DCI in SSset configured with group index 0, the remaining channel occupancyduration indicated by DCI format 2_0 ends, or the like.

When a value M is configured for a DL BWP in which SS set group indexesare configured, from the first “slot group” after at least P_switchnumber symbol(s) from the time point when SS set group switching istriggered, PDCCH monitoring may be started in SS set(s) corresponding tothe switched group index.

Referring to FIG. 9(d), it is illustrated a case that a time pointcorresponding to P symbols after the time point when SS set groupswitching is triggered is slot #1 based on 480 kHz SCS. In this case,PDCCH monitoring is performed in the SS set(s) corresponding to thegroup index before switching (i.e., SS set group #x) up to a specificsymbol position in slot #1, and from the specific symbol position inslot #1, SS set monitoring may be stopped. In addition, PDCCH monitoringmay be performed in SS set(s) corresponding to the switched group index(i.e., SS set group #y) from slot #4, corresponding to the boundary ofthe first “slot group” after slot #1.

Embodiment 5

The present disclosure relates to a method of applying a predeterminedtime interval starting from a PDCCH/DCI based on units of slot groups.

For example, the predetermined time interval may be defined as a timeinterval from slot A to slot B. The predetermined time interval mayinclude K0, K1, K2, etc. as shown in Table 8. The scope of the presentdisclosure is not limited to the examples of time intervals in Table 8,and includes application to time intervals related totransmission/reception timing dynamically indicated by DCI for DL BWPfor which M value is configured.

TABLE 8 slot A Slot B K0 Receiving DCI scheduling DL Receiving DL datadata (e.g., PDSCH) scheduled by DCI K1 Receiving DL data (e.g.,Transmitting HARQ-ACK PDSCH) corresponding to DL data K2 Receiving DCIscheduling UL Transmitting UL data data (e.g., PUSCH) scheduled by DCI

For example, for an active DL/UL BWP to which an M value is configured,the terminal may apply K0/K1/K2 value in units of slot groups.

For example, if the K0 value indicated in the DCI received in slot #n isn1, the terminal may expect PDSCH reception to start in slot #n+M*n1.

For example, if the K1 value indicated in the DCI received in slot #n isn2, the terminal may transmit HARQ-ACK PUCCH (in the corresponding ULBWP) after M*n2 slots from the last slot in which the PDSCH is received.

For example, if the value of K2 indicated in the DCI received in slot #nis n3, the terminal may start PUSCH transmission in slot #n+M*n3.

As a more specific example, the base station may configure with aterminal a set of X (X is an integer greater than or equal to 1) K0values (i.e., {first K0 value, second K0 value, third K0 value, . . . ,X-th K0 value}) through a higher layer signaling (e.g.,terminal-specific RRC signaling). Then, the base station may indicateany one among the set X K0 values through DL allocation (i.e., DL datascheduling) DCI. The terminal may perform DL data (e.g., PDSCH)reception based on the K0 value indicated through the DCI.

In addition, the base station may configure with a terminal a set of Y(Y is an integer greater than or equal to 1) K1 values (that is, {firstK1 value, second K1 value, third K1 value, . . . , Y-th K1 value})through a higher layer signaling (e.g., terminal-specific RRCsignaling). Then, the base station may indicate any one among the set YK1 values through DL allocation DCI. The terminal may perform HARQ-ACK(e.g., PUCCH) transmission for DL data based on the K1 value indicatedthrough the DL allocation DCI.

In addition, the base station may configure with a terminal a set of Z(Z is an integer greater than or equal to 1) K2 values (that is, {firstK2 value, second K2 value, third K2 value, . . . , Z-th K2 value})through a higher layer signaling (e.g., terminal-specific RRCsignaling). Then, the base station may indicate any one among the set ZK2 values through UL grant (i.e., UL data scheduling) DCI. The terminalmay perform UL data (e.g., PUSCH) transmission based on the K2 valueindicated through the UL grant DCI.

Here, for the active DL/UL BWP to which the M value is configured,K0/K1/K2 value may be applied in units of slot groups (i.e., M-slots).For active DL/UL BWP to which M value is not configured, K0/K1/K2 valuemay be applied in units of slots.

If the SCSs of slot A and slot B in Table 8 are different (that is, slotA and slot B belong to cells in which different SCSs are configured),K0/K1/K2 value may be defined based on the SCS of slot B. In addition,whether M value is configured for active DL/UL BWP may be determinedbased on the cell to which slot B belongs.

As an additional example, before the terminal receives information onthe set of K0/K1/K2 candidate(s) through RRC signaling, at least one ofa predefined default K0 value, default K1 value, or default K2 value maybe applied. When transmitting or receiving is performed in DL/UL BWPwhere the M value is configured (or when operating based on an SCSlarger than a predetermined SCS, or operating in FR3), a terminal mayapply the default K0/K1/K2 value in units of slot groups based on theabove-described default M value. When transmitting or receiving isperformed in DL/UL BWP where M value is not configured (or whenoperating based on an SCS less than or equal to a predetermined SCS, oroperating in FR1/FR2), the terminal may apply default K0/K1/K2 value inunits of slots.

As an additional example, depending on whether the M value is configured(or when operating based on an SCS less than or equal to/larger than apredetermined SCS, or when operating in FR1/FR2 or FR3), a terminal mayapply a predetermined time offset value in units of slot groups or inunits of slots. For example, the predetermined time offset value mayinclude a minimum scheduling offset (e.g., a time offset based onminimumSchedulingOffsetKO and/or minimumSchedulingOffsetK2 parameters)introduced to minimize unnecessary power consumption of the terminal.For example, when the minimumSchedulingOffsetKO value is configured as avalue of Q, the terminal may apply Q slots as offset values in the DL/ULBWP where the M value is not configured, and apply Q*M slots (i.e., Qslot groups) as an offset value in the DL/UL BWP where the M value isconfigured.

FIG. 10 is a diagram for illustrating a signaling procedure of a basestation and a terminal according to an embodiment of the presentdisclosure.

In step S1010, the base station may provide configuration of a slotgroup to the terminal. For example, the base station may configure an Mvalue for a DL BWP operating based on a specific SCS. For example, theslot group configuration may include activating the DL BWP with the SCScorresponding to the configuration index of μ_1 (e.g., SCS higher than120 kHz) (for example, μ_1=5 for 480 kHz SCS), and configuring the Mvalue as m (e.g., 4).

In step S1020, the base station may provide configuration for the SS setto the terminal. For example, the period of the SS set configured in theDL BWP based on a specific SCS may be configured as M-slot or larger, ora multiple of M-slot. For example, when M=m is configured, the period ofthe SS set may be configured as m*x (x is an integer greater than orequal to 1), and parameters for time domain characteristics of the SSset, such as offset and duration, may be additionally configured.

In step S1030, the terminal may perform SS set monitoring based on theslot group. For example, the maximum number of PDCCH candidates and/orthe maximum number of non-overlapping CCEs (i.e., BD/CCE upperlimit/budget) may be determined for each M-slot, SS sets exceeding theBD/CCE upper limit/budget may not be monitored or may be dropped foreach M-slot. For example, when M=m is configured, the terminal may applythe maximum number of PDCCH candidates and/or the maximum number ofnon-overlapping CCEs per m-slot, and whether the SS set beingmonitored/dropped may be determined based on whether the number of PDCCHcandidates and/or non-overlapping CCEs per m-slot exceeding the maximumnumber.

A combination of one or more of the above-described embodiments 1 to 5may be applied to the example of FIG. 10 , and redundant descriptionsare omitted.

As described above, unlike the existing frequency range/existing SCS inwhich the SS set period capable of configuring the PDCCH MO isconfigured as at least 1 slot, in case of PDCCH monitoring performed inevery slot even in a system supporting a new frequency range/new SCS(e.g., an SCS larger than the existing SCS), power consumption of theterminal may increase or implementation complexity may increase.Therefore, by defining/configuring M (M is an integer greater than 1)slots as slot groups according to various examples of the presentdisclosure, configuration and performing PDCCH monitoring in units ofslot groups may be supported, thereby reducing power consumption of theterminal. and reduce implementation complexity.

General Device to which the Present Disclosure May be Applied

FIG. 11 is a diagram which illustrates a block diagram of a wirelesscommunication system according to an embodiment of the presentdisclosure.

In reference to FIG. 11 , a first wireless device 100 and a secondwireless device 200 may transmit and receive a wireless signal through avariety of radio access technologies (e.g., LTE, NR).

A first wireless device 100 may include one or more processors 102 andone or more memories 104 and may additionally include one or moretransceivers 106 and/or one or more antennas 108. A processor 102 maycontrol a memory 104 and/or a transceiver 106 and may be configured toimplement description, functions, procedures, proposals, methods and/oroperation flow charts included in the present disclosure. For example, aprocessor 102 may transmit a wireless signal including firstinformation/signal through a transceiver 106 after generating firstinformation/signal by processing information in a memory 104. Inaddition, a processor 102 may receive a wireless signal including secondinformation/signal through a transceiver 106 and then store informationobtained by signal processing of second information/signal in a memory104. A memory 104 may be connected to a processor 102 and may store avariety of information related to an operation of a processor 102. Forexample, a memory 104 may store a software code including commands forperforming all or part of processes controlled by a processor 102 or forperforming description, functions, procedures, proposals, methods and/oroperation flow charts included in the present disclosure. Here, aprocessor 102 and a memory 104 may be part of a communicationmodem/circuit/chip designed to implement a wireless communicationtechnology (e.g., LTE, NR). A transceiver 106 may be connected to aprocessor 102 and may transmit and/or receive a wireless signal throughone or more antennas 108. A transceiver 106 may include a transmitterand/or a receiver. A transceiver 106 may be used together with a RF(Radio Frequency) unit. In the present disclosure, a wireless device maymean a communication modem/circuit/chip.

A second wireless device 200 may include one or more processors 202 andone or more memories 204 and may additionally include one or moretransceivers 206 and/or one or more antennas 208. A processor 202 maycontrol a memory 204 and/or a transceiver 206 and may be configured toimplement description, functions, procedures, proposals, methods and/oroperation flows charts included in the present disclosure. For example,a processor 202 may generate third information/signal by processinginformation in a memory 204, and then transmit a wireless signalincluding third information/signal through a transceiver 206. Inaddition, a processor 202 may receive a wireless signal including fourthinformation/signal through a transceiver 206, and then store informationobtained by signal processing of fourth information/signal in a memory204. A memory 204 may be connected to a processor 202 and may store avariety of information related to an operation of a processor 202. Forexample, a memory 204 may store a software code including commands forperforming all or part of processes controlled by a processor 202 or forperforming description, functions, procedures, proposals, methods and/oroperation flow charts included in the present disclosure. Here, aprocessor 202 and a memory 204 may be part of a communicationmodem/circuit/chip designed to implement a wireless communicationtechnology (e.g., LTE, NR). A transceiver 206 may be connected to aprocessor 202 and may transmit and/or receive a wireless signal throughone or more antennas 208. A transceiver 206 may include a transmitterand/or a receiver. A transceiver 206 may be used together with a RFunit. In the present disclosure, a wireless device may mean acommunication modem/circuit/chip.

Hereinafter, a hardware element of a wireless device 100, 200 will bedescribed in more detail. It is not limited thereto, but one or moreprotocol layers may be implemented by one or more processors 102, 202.For example, one or more processors 102, 202 may implement one or morelayers (e.g., a functional layer such as PHY, MAC, RLC, PDCP, RRC,SDAP). One or more processors 102, 202 may generate one or more PDUs(Protocol Data Unit) and/or one or more SDUs (Service Data Unit)according to description, functions, procedures, proposals, methodsand/or operation flow charts included in the present disclosure. One ormore processors 102, 202 may generate a message, control information,data or information according to description, functions, procedures,proposals, methods and/or operation flow charts included in the presentdisclosure. One or more processors 102, 202 may generate a signal (e.g.,a baseband signal) including a PDU, a SDU, a message, controlinformation, data or information according to functions, procedures,proposals and/or methods disclosed in the present disclosure to provideit to one or more transceivers 106, 206. One or more processors 102, 202may receive a signal (e.g., a baseband signal) from one or moretransceivers 106, 206 and obtain a PDU, a SDU, a message, controlinformation, data or information according to description, functions,procedures, proposals, methods and/or operation flow charts included inthe present disclosure.

One or more processors 102, 202 may be referred to as a controller, amicro controller, a micro processor or a micro computer. One or moreprocessors 102, 202 may be implemented by a hardware, a firmware, asoftware, or their combination. In an example, one or more ASICs(Application Specific Integrated Circuit), one or more DSPs (DigitalSignal Processor), one or more DSPDs (Digital Signal Processing Device),one or more PLDs (Programmable Logic Device) or one or more FPGAs (FieldProgrammable Gate Arrays) may be included in one or more processors 102,202. Description, functions, procedures, proposals, methods and/oroperation flow charts included in the present disclosure may beimplemented by using a firmware or a software and a firmware or asoftware may be implemented to include a module, a procedure, afunction, etc. A firmware or a software configured to performdescription, functions, procedures, proposals, methods and/or operationflow charts included in the present disclosure may be included in one ormore processors 102, 202 or may be stored in one or more memories 104,204 and driven by one or more processors 102, 202. Description,functions, procedures, proposals, methods and/or operation flow chartsincluded in the present disclosure may be implemented by using afirmware or a software in a form of a code, a command and/or a set ofcommands.

One or more memories 104, 204 may be connected to one or more processors102, 202 and may store data, a signal, a message, information, aprogram, a code, an instruction and/or a command in various forms. Oneor more memories 104, 204 may be configured with ROM, RAM, EPROM, aflash memory, a hard drive, a register, a cash memory, a computerreadable storage medium and/or their combination. One or more memories104, 204 may be positioned inside and/or outside one or more processors102, 202. In addition, one or more memories 104, 204 may be connected toone or more processors 102, 202 through a variety of technologies suchas a wire or wireless connection.

One or more transceivers 106, 206 may transmit user data, controlinformation, a wireless signal/channel, etc. mentioned in methods and/oroperation flow charts, etc. of the present disclosure to one or moreother devices. One or more transceivers 106, 206 may receiver user data,control information, a wireless signal/channel, etc. mentioned indescription, functions, procedures, proposals, methods and/or operationflow charts, etc. included in the present disclosure from one or moreother devices. For example, one or more transceivers 106, 206 may beconnected to one or more processors 102, 202 and may transmit andreceive a wireless signal. For example, one or more processors 102, 202may control one or more transceivers 106, 206 to transmit user data,control information or a wireless signal to one or more other devices.In addition, one or more processors 102, 202 may control one or moretransceivers 106, 206 to receive user data, control information or awireless signal from one or more other devices. In addition, one or moretransceivers 106, 206 may be connected to one or more antennas 108, 208and one or more transceivers 106, 206 may be configured to transmit andreceive user data, control information, a wireless signal/channel, etc.mentioned in description, functions, procedures, proposals, methodsand/or operation flow charts, etc. included in the present disclosurethrough one or more antennas 108, 208. In the present disclosure, one ormore antennas may be a plurality of physical antennas or a plurality oflogical antennas (e.g., an antenna port). One or more transceivers 106,206 may convert a received wireless signal/channel, etc. into a basebandsignal from a RF band signal to process received user data, controlinformation, wireless signal/channel, etc. by using one or moreprocessors 102, 202. One or more transceivers 106, 206 may convert userdata, control information, a wireless signal/channel, etc. which areprocessed by using one or more processors 102, 202 from a basebandsignal to a RF band signal. Therefore, one or more transceivers 106, 206may include an (analogue) oscillator and/or a filter.

Embodiments described above are that elements and features of thepresent disclosure are combined in a predetermined form. Each element orfeature should be considered to be optional unless otherwise explicitlymentioned. Each element or feature may be implemented in a form that itis not combined with other element or feature. In addition, anembodiment of the present disclosure may include combining a part ofelements and/or features. An order of operations described inembodiments of the present disclosure may be changed. Some elements orfeatures of one embodiment may be included in other embodiment or may besubstituted with a corresponding element or a feature of otherembodiment. It is clear that an embodiment may include combining claimswithout an explicit dependency relationship in claims or may be includedas a new claim by amendment after application.

It is clear to a person skilled in the pertinent art that the presentdisclosure may be implemented in other specific form in a scope notgoing beyond an essential feature of the present disclosure.Accordingly, the above-described detailed description should not berestrictively construed in every aspect and should be considered to beillustrative. A scope of the present disclosure should be determined byreasonable construction of an attached claim and all changes within anequivalent scope of the present disclosure are included in a scope ofthe present disclosure.

A scope of the present disclosure includes software ormachine-executable commands (e.g., an operating system, an application,a firmware, a program, etc.) which execute an operation according to amethod of various embodiments in a device or a computer and anon-transitory computer-readable medium that such a software or acommand, etc. are stored and are executable in a device or a computer. Acommand which may be used to program a processing system performing afeature described in the present disclosure may be stored in a storagemedium or a computer-readable storage medium and a feature described inthe present disclosure may be implemented by using a computer programproduct including such a storage medium. A storage medium may include ahigh-speed random-access memory such as DRAM, SRAM, DDR RAM or otherrandom-access solid state memory device, but it is not limited thereto,and it may include a nonvolatile memory such as one or more magneticdisk storage devices, optical disk storage devices, flash memory devicesor other nonvolatile solid state storage devices. A memory optionallyincludes one or more storage devices positioned remotely fromprocessor(s). A memory or alternatively, nonvolatile memory device(s) ina memory include a non-transitory computer-readable storage medium. Afeature described in the present disclosure may be stored in any one ofmachine-readable mediums to control a hardware of a processing systemand may be integrated into a software and/or a firmware which allows aprocessing system to interact with other mechanism utilizing a resultfrom an embodiment of the present disclosure. Such a software or afirmware may include an application code, a device driver, an operatingsystem and an execution environment/container, but it is not limitedthereto.

Here, a wireless communication technology implemented in a wirelessdevice 100, 200 of the present disclosure may include NarrowbandInternet of Things for a low-power communication as well as LTE, NR and6G. Here, for example, an NB-IoT technology may be an example of a LPWAN(Low Power Wide Area Network) technology, may be implemented in astandard of LTE Cat NB1 and/or LTE Cat NB2, etc. and is not limited tothe above-described name. Additionally or alternatively, a wirelesscommunication technology implemented in a wireless device 100, 200 ofthe present disclosure may perform a communication based on a LTE-Mtechnology. Here, in an example, a LTE-M technology may be an example ofa LPWAN technology and may be referred to a variety of names such as aneMTC (enhanced Machine Type Communication), etc. For example, an LTE-Mtechnology may be implemented in at least any one of various standardsincluding 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL(non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication,and/or 7) LTE M and so on and it is not limited to the above-describedname. Additionally or alternatively, a wireless communication technologyimplemented in a wireless device 100, 200 of the present disclosure mayinclude at least any one of a ZigBee, a Bluetooth and a low power widearea network (LPWAN) considering a low-power communication and it is notlimited to the above-described name. In an example, a ZigBee technologymay generate PAN (personal area networks) related to a small/low-powerdigital communication based on a variety of standards such as IEEE802.15.4, etc. and may be referred to as a variety of names.

A method proposed by the present disclosure is mainly described based onan example applied to 3GPP LTE/LTE-A, 5G system, but may be applied tovarious wireless communication systems other than the 3GPP LTE/LTE-A, 5Gsystem.

1-27. (canceled)
 28. A method performed by a terminal in a wirelesscommunication system, the method comprising: receiving at least onephysical downlink control channel (PDCCH) candidate on an activedownlink bandwidth part on a serving cell according to at least onesearch space (SS) set for maximum numbers of PDCCH candidates andnon-overlapping control channel elements (CCEs) per a group of M slots;and decoding the at least one PDCCH candidate according to monitoreddownlink control information (DCI) format, wherein M is a number ofconsecutive slots, wherein multiple groups of M slots are consecutiveand non-overlapping, wherein, based on the terminal not being providedconfiguration information for monitoring capability for the servingcell, a pre-defined value of M is applied for a specific subcarrierspacing (SCS) configuration.
 29. The method according to claim 28,wherein: for SCS configuration index 5, the pre-defined value of M is 4,and for SCS configuration index 6, the pre-defined value of M is
 8. 30.The method according to claim 28, wherein: based on the terminal beingprovided the configuration information for monitoring capability for theserving cell, the terminal obtains an indication to monitor PDCCH on theserving cell for maximum numbers of PDCCH candidates and non-overlappingCCEs per the group of M slots based on the configuration information formonitoring capability.
 31. The method according to claim 28, wherein:for SCS configuration index 5 or 6, a capability to monitor PDCCHrelated to the group of M slots is indicated by the terminal.
 32. Themethod according to claim 28, wherein: for SCS configuration index 5,based on a value of M being 4, the maximum number of monitored PDCCHcandidates per a group of M slots is 20, and the maximum number ofnon-overlapped CCEs in a group of M slots is 32, and for SCSconfiguration index 6, based on a value of M being 8, the maximum numberof monitored PDCCH candidates per a group of M slots is 20, and themaximum number of non-overlapped CCEs in a group of M slots is
 32. 33.The method according to claim 28, wherein: at least one of a period,offset, or duration of the at least one SS set is based on a value of M.34. The method according to claim 33, wherein: at least one of theperiod or the offset of the at least one SS set corresponds to aninteger multiple of M slots, the duration of the at least one SS setcorresponds to be equal to or less than the period that is the integermultiple of M slots.
 35. The method according to claim 33, wherein: theat least one SS set is determined, according to an order of SS setindex, based on a number of counted PDCCH candidates not exceeding amaximum number of monitored PDCCH candidates per a group of M slots, andbased on a counted number of non-overlapping CCEs not exceeding amaximum number of non-overlapping CCEs in a group of M slots.
 36. Themethod according to claim 33, wherein: based on SS set group switchingbeing triggered for the terminal, monitoring of switched SS set group isstarted at a beginning of a first slot of group of M slots that is apredetermined time length after a time point of triggering.
 37. Aterminal in a wireless communication system, the terminal comprising: atleast one transceiver; and at least one processor connected to the atleast one transceiver, wherein the at least one processor is configuredto: receive, through the at least one transceiver, at least one physicaldownlink control channel (PDCCH) candidate on an active downlinkbandwidth part on a serving cell according to at least one search space(SS) set for maximum numbers of PDCCH candidates and non-overlappingcontrol channel elements (CCEs) per a group of M slots; and decode theat least one PDCCH candidate according to monitored downlink controlinformation (DCI) format, wherein M is a number of consecutive slots,wherein multiple groups of M slots are consecutive and non-overlapping,wherein, based on the terminal not being provided configurationinformation for monitoring capability for the serving cell, apre-defined value of M is applied for a specific subcarrier spacing(SCS) configuration.
 38. A base station in a wireless communicationsystem, the terminal comprising: at least one transceiver; and at leastone processor connected to the at least one transceiver, wherein the atleast one processor is configured to: code a downlink controlinformation (DCI) according to a DCI format; and transmit, to a terminalthrough the at least one transceiver, the DCI via a physical downlinkcontrol channel (PDCCH), the PDCCH corresponding to one of at least onePDCCH candidate received by the terminal on an active downlink bandwidthpart on a serving cell according to at least one search space (SS) setfor maximum numbers of PDCCH candidates and non-overlapping controlchannel elements (CCEs) per a group of M slots, wherein M is a number ofconsecutive slots, wherein multiple groups of M slots are consecutiveand non-overlapping, wherein, based on the terminal not being providedconfiguration information for monitoring capability for the servingcell, a pre-defined value of M is applied for a specific subcarrierspacing (SCS) configuration.